Category: jetpack.com

If you have a WordPress site, it’s important that you have enough memory allocated to run the software smoothly. Depending on your site’s size and complexity, you may need to increase it. However, before you do, you’ll need to determine your current memory limit.

In this article, we’ll show you how to check your current WordPress memory limit and how to increase it if necessary, as well as answer some of the most frequently asked questions about WordPress memory limits.

What is the PHP memory limit in WordPress?

The PHP memory limit is the maximum amount of memory that a PHP script can use. If a WordPress site exceeds its PHP memory limit, it will likely experience errors. These errors can include the “white screen of death,” slow page loading, and database connection issues.

Often, the error will appear as follows:

“Fatal error: Allowed memory size of XXXXXXX bytes exhausted (tried to allocate YYYYYYY bytes) in /path/to/file.php on line ZZZ.”

You’ll come across this error when trying to install WordPress plugins or themes, run updates, or perform some other action on your site.

How to check your WordPress memory limit

There are a few ways to check your WordPress memory limit:

1. Check your WordPress hosting account.
2. Check your wp-config.php file.
3. Ask your WordPress host.
4. Use WordPress Site Health.
5. Use a WordPress plugin.

Let’s review each of these options in more detail.

1. Check your WordPress hosting account

The first place to check your WordPress memory limit is in your hosting account. Many hosts will list the current PHP memory limit in the account control panel. In cPanel, this is located under the Software section. Click PHP Selector, then navigate to the document root of the directory you’d like to work with. You’ll likely see information as follows and this will tell you which PHP version your site is currently using: 

Then, go to Options and scroll down until you see the line that reads memory_limit. Your site’s current settings should be visible here. 

2. Check your wp-config.php file

The second place you can check your WordPress memory limit is in the wp-config.php file. This file is located in the root directory of your WordPress site. To access it, you’ll need to connect to your site using an FTP client like Filezilla or through the File Manager in cPanel. Once you’re connected, open the wp-config.php file in a text editor like Notepad++.

Next, search for the following line of code:

define('WP_MEMORY_LIMIT', '256M');

This line of code defines the maximum amount of memory that can be used by WordPress. The number following WP_MEMORY_LIMIT represents the maximum memory limit in megabytes. In this example, it’s set to 256MB.

If this line is not present in your wp-config.php file, you can add it to the end of the file. Be sure to save your changes before exiting.

3. Ask your WordPress host

If you’re not sure where to find your WordPress memory limit or you’re unable to access your hosting account or wp-config.php file, you can always contact your WordPress host and ask them what the current PHP memory limit is for your site. To do this, you’ll typically need to open a support ticket with your host or send them an email.

4. Use WordPress Site Health

If you want an easy way to check your WordPress memory limit (and other site details), you can use the WordPress built-in Site Health tool, which gives you an overview of your site’s health, including the current PHP memory limit. 

This module will show you the current memory limit for your WordPress site. To access it, go to Tools → Site Health in your WordPress dashboard and click on the Info tab. Expand Media Handling and, under Server, look for the PHP memory limit. 

5. Use a plugin

Another option is to use a plugin to get access to this information. Here are two that are up for the task: 

• WP Healthcheck: This plugin gives you an overview of your WordPress site’s health, including the current memory limit. Plus, it helps improve your site performance by removing transients and other unnecessary data. 
• Health Check & Troubleshooting: In addition to presenting your memory limit and other server information in an easy-to-consume way, this tool identifies configuration and setup issues. This can be extremely helpful if you’re working with a support team to troubleshoot a problem. 

How to increase the WordPress memory limit

If you need to increase your WordPress memory limit, here’s the optimal process to follow:

1. Back up your site before editing any code
2. Edit wp_memory_limit in your wp-config.php file

In some cases, you may also need to take the following additional steps:

3. Edit memory_limit in your PHP.ini file
4. Edit your .htaccess file
5. Contact your hosting provider

Let’s review each of these in more detail.

1. Back up your site before editing any code

Before you make any changes to your WordPress site, it’s important to back up your data first. This will ensure that you have a copy of your site that you can revert back to if something goes wrong. There are a few different ways to back up your WordPress site:

• Use a WordPress backup plugin like Jetpack Backup
• Manually export your WordPress database
• Use a staging environment
• Use server snapshots (if available)
• Ask your WordPress host if they offer backups

Jetpack provides the simplest method of backing up your WordPress site. You can download a copy in just a few clicks without having to deal with accessing your server. And if something goes wrong while increasing your memory limit, you can restore that backup even if your website is completely down. The best part? In the future, you’ll be protected with automated, real-time backups that save your site every single time a change occurs.

Learn more about how to back up your WordPress site with Jetpack.

2. Edit wp_memory_limit in your wp-config.php file

If you want to increase your WordPress memory limit, the first place to start is with your wp-config.php file. This file is located in the root directory of your WordPress site. You can navigate here using an FTP client or through the File Manager in cPanel as previously mentioned.

To edit your wp_memory_limit, simply download the file and open it in a text editor. Then look for the line that says:

define('WP_MEMORY_LIMIT', '64M');

Replace the memory limit with a higher number. For example, if you wanted to increase your memory limit to 256M, you would use:

define('WP_MEMORY_LIMIT', '256M');

Save your changes. Upload the file back to your server. Your site’s memory limit should now be increased. 

3. Edit memory_limit in your PHP.ini file

If you’re unable to edit the wp_memory_limit in your wp-config.php file, or if you want to increase the memory limit for more than just WordPress, you can edit the memory_limit setting in your PHP.ini file.

The PHP.ini file is located in the root directory of your WordPress site, but if your hosting provider uses cpanel, you can easily change the memory limit from that dashboard. 

Navigate to cpanel, and find the MultiPHP INI Editor in the Software section. From the dropdown that appears, select your website. Look for “memory_limit” and change it to whatever number you’d like. Save your changes. Your memory limit should now be increased.

4. Edit your .htaccess file

If you’re still unable to increase your WordPress memory limit using the previous methods, you can try adding the following line of code to your .htaccess file:

php_value memory_limit 256M

The .htaccess file is located in the root directory of your WordPress site. If you don’t see this file, make sure that you’ve enabled hidden files in your FTP client. 

You can do this by going to the Server or Connection settings in your FTP client and checking the box that says Show hidden files. You can do this in cPanel as well by going to File Manager, clicking Settings in the top right corner then checking the box that reads Show Hidden Files (dotfiles). 

5. Contact your hosting provider

If you’ve tried all of the above and you’re still unable to increase your WordPress memory limit, your last resort is to contact your hosting provider. You may need to upgrade your hosting plan to accomplish this, especially if you’ve used up your resources. 

Your host should be able to help you increase your memory limit and point you in the right direction if you need to upgrade your hosting plan to something more robust, like a managed WordPress hosting plan, or even a VPS or dedicated server. 

Frequently asked questions

Here are some answers to common questions people have about the WordPress memory limit:

1. Why increase the WordPress memory limit?

There are a few reasons why you might need to increase your WordPress memory limit:

• Your site is loading slowly
• You’re seeing white screen of death errors
• You’re seeing “out of memory” errors
• Your hosting provider recommends it

2. What is the recommended wp_memory_limit?

The general rule of thumb is that you should have at least 64MB of memory allocated for WordPress. However, this can vary depending on the size and complexity of your site. If you’re not sure how much memory your site needs, you can start with 64MB and increase it as needed.

3. How do I know if I need to increase my WordPress memory limit?

There are a few signs that you may need to increase your WordPress memory limit:

• You see an error message saying, “Allowed memory size exhausted” 
• You see an error message saying, “WordPress has encountered an error and needs to restart”
• Your site is loading slowly or timing out
• You’re seeing “white screen of death” errors

4. What happens if I don’t increase my WordPress memory limit?

If you don’t increase your WordPress memory limit, you may see errors on your site, or your site may load slowly. In some cases, it may even crash.

5. Will increasing my WordPress memory limit slow down my site?

Generally speaking, no. However, if you allocate too much memory to WordPress, it can cause your server to slow down and impact your site speed.

6. What happens if I try to allocate more memory than my server has?

If you try to allocate more memory to WordPress than your server has, you’ll see an error message saying “Fatal error: Allowed memory size of xxxxxxx bytes exhausted.” This means that you need to increase the amount of memory your server has, or reduce the amount of memory WordPress is trying to use.

7. What is the maximum WordPress memory limit?

The maximum memory limit for WordPress is 512MB. However, depending on your server and WordPress settings, you may not be able to allocate this much memory to WordPress.

8. What’s the difference between wp_memory_limit and wp_max_memory_limit?

The wp_memory_limit setting defines the maximum amount of memory that can be used by WordPress. The wp_max_memory_limit setting defines the maximum amount of memory that can be used by WordPress and any plugins or themes. If you’re having errors with a plugin or theme, you may need to increase the wp_max_memory_limit setting.

9. I’m still having problems. What should I do?

If you’ve tried all of the above and you’re still having problems, your best bet is to contact your hosting provider and ask them for help. They’ll be able to take a look at your server and WordPress settings and help you figure out what’s going on.

Increase your WordPress memory limit

Learning things like how to increase your WordPress memory limit is an exciting part of expanding your skills as a site owner. We hope you’ve found this post helpful. If you’re still seeing errors or slow performance, we recommend contacting your hosting provider for help.

WordPress is one of the most versatile and robust content management systems (CMSs) out there. Still, you may occasionally run into some issues when using it. One of those is an error informing you that “your PHP installation appears to be missing the MySQL extension which is required by WordPress.”

The good news is that this is a relatively straightforward problem with a handful of quick and easy solutions. Once you understand what the error means and the common causes of it, you’ll be better prepared to resolve it and prevent it from happening again. 

Below, we’ll explain what the WordPress MySQL extension error is and some of its common causes. Then, we’ll walk you through how to fix the problem as well as how to prevent it from happening again. 

What is the WordPress MySQL extension error?

Before we get into resolving this error message, it’s important to understand what it means. So let’s go over some basics. 

First of all, Hypertext Preprocessor (PHP) is a server-side scripting language designed for web development. It’s also the most popular scripting language today, as well as the primary language of WordPress.

MySQL is a database management system used by WordPress to store your site’s information. This is where you can find all of your database tables and files. 

When you’re working on your website, you may come across the “Your PHP installation appears to be missing the MySQL extension which is required by WordPress” error message. If you’ve never encountered this issue, you may be confused as to what it means, let alone how to fix it. 

This error message will usually show up when you try to install or update WordPress. Although an error message like this can be frustrating and stressful, there’s no need to panic.

What causes the MySQL extension error on WordPress?

There are a handful of reasons you might be dealing with this problem. Typically, it means that something is wrong with your site’s code. As the error message indicates, some element is preventing WordPress from properly connecting to the MySQL database. 

One of the most common causes of the error is that your server does not have the MySQL extension installed or enabled. Usually, this can be attributed to one of two things:

First, you may be using an incompatible version of PHP. MySQL 5.0 requires PHP 5.2 or higher. WordPress recommends using the latest stable version of PHP, which is currently PHP 7.4.

If you’re using a particularly outdated version of WordPress with a modern version of PHP, this error can also happen. PHP 7.0 deprecated the MySQL extension and WordPress now uses the newer PDO_MySQL or MySQLi extensions.

The other possibility is that your PHP is misconfigured, meaning it’s not properly set up to work with your WordPress site. In addition to being outdated or incompatible, it could be due to incorrect server settings.

How to fix the “Your PHP installation appears to be missing the MySQL extension which is required by WordPress” error

Now that you understand more about what the message means and what may be causing it, let’s take a look at how to resolve it. 

1. Update WordPress

As we mentioned, using an older version of WordPress, like 3.9 or lower, might cause this error message. Therefore, one of the first steps you should take to resolve it is to make sure that you’re using the most updated version of WordPress Core. 

This is likely the source of the problem if you’re using the latest version of PHP (which we’ll cover in the next section). To determine whether there’s an update available, you can navigate to your admin area and go to Dashboard → Updates.

Note that if you’re using a WordPress.com site, you can find updates under My Home →  Updates, instead. Any available updates will be shown on this screen.

It will also inform you of what version of WordPress you’re currently using. If you see a notification saying “An updated version of WordPress is available,” you can select the Update to version [X] button. 

On this page, you can also view any plugin and theme updates that are available. As with WordPress Core, plugins can present compatibility issues with PHP that may result in the MySQL extension error. 

So, we also recommend updating any plugins that have newer versions available. If there are multiple, you can simply select all, then click on Update Plugins.

2. Check your PHP version

Once you’re sure that your WordPress core is up to date, the next step is to check which version of PHP your server is using. There are a couple of ways to go about this.

The easiest option is to navigate to Tools → Site Health from your WordPress dashboard.

Next, you can select the Info tab, then scroll down and expand the Server panel. Under this section, you can locate the PHP version you’re currently running.

If you’re not able to access your WordPress admin, you can check your PHP version by connecting to your server via a File Transfer Protocol (FTP) client like FileZilla. Alternatively, if your web host uses cPanel, you can use the File Manager tool. 

Either in your FTP client or your File Manager, create a new file in the root directory of your site (/public_html) and name it phpinfo.php. Next, open the file and copy and paste the following code snippet:

<?php phpinfo(); ?>

Save the file when you’re done. Then, in a new browser tab, visit “yoursite.com/phpinfo.php”. Be sure to replace “yoursite.com” with your domain name. 

Now you should see a page that displays your server’s PHP configuration information.

The PHP version your server is running should be listed at the top of the screen. If it begins with 7 or 8, an outdated version of PHP probably isn’t the reason you’re seeing the error message. 

If you’re using PHP 5.X, you should consider updating your PHP version. 

3. Ensure the MySQL extension is installed

If your WordPress version is up to date, it’s important to also check whether the MySQL extension is installed and enabled. It’s possible that the Operating System (OS) you’re using didn’t include the extension by default, which means you’ll have to install it yourself. 

To determine whether it’s installed, revisit the phpinfo.php file that you created in the last step. Then, navigate to the mysqli or mysql section. If the MySQL extension is installed, it will indicate the version of it next to the Client API field.

But, if this field is blank or not visible at all, it means that the MySQL extension is not installed. The process for installation will depend on your host. You can refer to the PHP installation guide for details.

If your provider uses cPanel, you can enable the extension by navigating to Software from your cPanel dashboard, then choosing Select PHP Version.

Here, select the most recent version of PHP, then click on the boxes for mysqli and mysqlnd. Save your changes, then revisit your site to see if you’re still seeing the error message.

Alternatively, if you’re unsure about installing the MySQL extension on your own, you may want to reach out to your web host. You can always request that they complete this process for you.

4. Verify that the PHP extension is properly configured

Once you know that your WordPress version is up to date and the MySQL extension is installed, you can safely confirm that something else is causing the problem. Another reason you might be seeing the error message is that the extension is not configured correctly. 

There are a few issues that can lead to misconfiguration, including incorrect file paths or using a php.ini file intended for a different type of server. For instance, you may be using one meant for Windows servers on a Linux server. 

To verify that your PHP extension is configured properly, navigate back to your phpinfo.php file. Then, locate the Loaded Configuration File item.

This is where you can find the file path value. Note the file path listed here, then look for the extension_dir row.

The file path listed here should match what is listed for the Loaded Configuration File. If not, the next step is to edit your php.ini file to correct it. When you’re done, revisit your site to make sure the error is resolved. 

Tips for preventing the MySQL extension error in WordPress from happening again

At this point, you’ve learned how to fix the MySQL extension error in WordPress. But there are also steps that you can take to prevent it from happening in the future. 

The first is to back up your WordPress site in real time. Keeping updated copies of your site files can make it easier to identify the source of issues as they occur. When you use a solution like Jetpack, you can also ensure that you always have an updated version of your site to restore in the event that something goes wrong. 

It’s also crucial to make sure you’re keeping your WordPress software up to date. Not only can this help prevent errors like the MySQL extension issue, but it can provide security and performance enhancements for your site as well. 

Finally, be sure to choose a WordPress web host that uses updated versions of PHP. When providers automatically handle these updates for you, this eliminates the need to manually manage it yourself. They can also help streamline server configuration to ensure that you’re adhering to best practices. 

In turn, this can reduce the likelihood of running into PHP-related errors. There are a wide variety of high-quality and reliable WordPress hosts to choose from. Some of the top WordPress hosts include Bluehost, DreamHost, and Pressable. 

Streamline WordPress website maintenance

WordPress is a powerful and dependable CMS, but you can still run into issues from time to time when using it. You might encounter an error message informing you that “Your PHP installation appears to be missing the MySQL extension which is required by WordPress.” Fortunately, there are a handful of solutions you can use to resolve this problem.

As we discussed, there are four measures you can take to fix this error in WordPress:

1. Update your WordPress software and plugins.
2. Check your PHP version and update it, if necessary.
3. Ensure that the MySQL extension is installed.
4. Verify that the PHP extension is properly configured. 

To help prevent WordPress errors from happening in the future and to make troubleshooting and resolving any issues easier, it’s important to back up your site in real time. Learn how Jetpack Backup can make this a breeze!

If you’re just getting started with WordPress development, one of the most important files you should familiarize yourself with is the functions.php file. There are actually three possible functions.php files that you might use on your WordPress website, and each plays a different role. Knowing where these files live, what their purpose is, and how and when to modify them will help you when troubleshooting issues and give you more control over your site’s functionality.

In this article, we’ll cover everything you need to know about WordPress functions.php files. You’ll learn what functions.php does and how to find and edit it. We’ll even include a few useful code snippets to try out. 

You can start at the beginning and read through or jump to a specific section using the table of contents below:

• What is functions.php in WordPress?
• Where is the functions.php file located?
• How to access functions.php
  • Accessing functions.php in your WordPress Admin Interface
  • Accessing functions.php via FTP
  • Accessing functions.php in your cPanel
• When should I edit functions.php in WordPress?
• How to edit functions.php in WordPress
  • Editing functions.php in your WordPress Theme File Editor
  • Editing functions.php with a text editor
  • Editing functions.php directly in cPanel
• Using a plugin to add functions to your WordPress site
• How to protect functions.php from security exploits
• What code can I add to functions.php in WordPress?
• FAQ
  • Do I need to create a child theme to edit functions.php?
  • How do I restore functions.php from a backup if I don’t have access to my WordPress dashboard?
  • Can I add JavaScript to my functions.php file?

What is functions.php in WordPress?

In WordPress, the functions.php file is where vital code lives that determines the way your site works. There are actually at least two functions.php files in every WordPress website — one included with WordPress core and one included with your theme. If you’re using a child theme, you should also have a functions.php in your child theme folder. 

The functions.php file in WordPress core contains important code that’s required for WordPress to function. You should almost never modify the code in WordPress core’s functions.php file. 

Your theme’s functions.php file is where all the theme-specific features of your website live — like custom menu locations, widget areas, custom header and footer content and functionality, post excerpt length, and more. 

Your theme’s functions.php file behaves in much the same way as a WordPress plugin. The difference is that functions.php should be used for code that is theme-specific, while plugins should be used for functionality that will remain even when you switch themes.

Where is the functions.php file located?

We’ve talked about what the functions.php file does both in WordPress core and in the theme files, but how do you find the functions.php file? Where is functions.php in WordPress? 

All of your WordPress files are located in your site’s root directory and in various subfolders. Your root directory is usually named something like public_html or www, but may have a different name. If you aren’t sure where to find your WordPress installation folder on your server, contact your web host.

Once you’ve found where your WordPress files are located on your server, you can start looking for your functions.php files. We’ve mentioned that there are up to three locations for functions.php: WordPress core, your theme folder, and your child theme folder. In this section we’ll go over where to find each one. 

Where is functions.php in WordPress core?

If you’re looking for the location of functions.php in WordPress core, you’ll find it in the wp-includes folder of your WordPress installation. 

While you should never edit functions.php in WordPress core, you may find yourself needing to inspect it for one reason or another. The most likely scenario for poking around in functions.php in WordPress core is if you suspect that malware has been injected into it. 

Before even opening functions.php, you should make a backup of your WordPress site in case you accidentally make a change to the file that causes a critical error. If you find that functions.php has been corrupted or hacked, chances are you may have other areas of WordPress that are affected. The best thing to do is simply replace WordPress with a fresh installation, rather than trying to remove all the offending scripts one-by-one.

Where is functions.php in my WordPress theme folder?

Your theme’s functions.php file is located in the main directory of your theme folder: wp-content → themes → yourtheme.

Where is functions.php in the WordPress child theme folder?

The WordPress child theme functions.php file is located in the main directory of your child theme folder: wp-content → themes → yourtheme-child.

How do I access functions.php?

Knowing where functions.php lives is only half the job. Now comes the question of how to access functions.php in WordPress. While the functions.php file in WordPress core can only be accessed through secure file transfer protocol (SFTP) or through cPanel, your theme and child theme functions.php files can also be accessed in the WordPress Theme File Editor. 

Accessing functions.php in the WordPress Theme File Editor

If you need to access your theme or child theme’s functions.php file, you can do so directly from the WordPress Theme File Editor. In your WordPress dashboard, go to Appearance → Theme File Editor.

You’ll be taken to the Edit Themes page. From here, under the dropdown next to Select theme to edit, choose your theme and click Select. You’ll see a list of files available to edit under the Theme Files column at the far right of your screen. Click functions.php to open the file.

If you’re in your parent theme’s functions.php file, you’ll see a warning notice on the bottom of the screen above the Update File button that says, “Caution: This is a file in your current parent theme.” 

Note: If you’re not the theme developer, you should make your changes in your child theme’s functions.php file to avoid having your edits overwritten in future theme updates.

Accessing functions.php via SFTP

Step 1: Install your SFTP client. If you don’t have an SFTP client already, you’ll need to download one. There are some great free and premium options out there, including: 

Application	System	Free or Premium
WinSCP	Windows	Free
Filezilla	Windows, Mac, Linux	Free and premium options
Cyberduck	Windows, Mac	Free
Transmit	Mac	Premium

In this example, we’ll be using Filezilla. Other SFTP clients should work in a similar fashion.

Step 2: Retrieve your SFTP credentials. To log into your server via SFTP you’ll need the following details:

• Host (your server’s IP address or url)
• SFTP username
• Password
• Port number

These details can usually be found in your hosting control panel. This information might be generated for you or your host may prompt you to create an SFTP username and password. If you don’t know where to find these credentials or have trouble figuring out how to create them, search your host’s help documentation for instructions or contact their support team. 

Step 3: Enter your SFTP credentials.

Enter your host’s IP address or url, your SFTP username, password, and the port number (usually 22 or 2222, but some hosts may use a different port).

Note: You might get a ‘host key unknown’ alert if your SFTP client uses trust on first use (TOFU) authentication. Check ‘Always trust this host, add this key to the cache’ if you plan on using your SFTP client to access the site again. Click OK to proceed.

Step 4: Navigate to your website’s root directory.

Once you’ve logged in, you’ll see two file trees displayed at the button of your screen  — one on the left and one on the right. The right side lists the directories on your web server (remote). The left side lists the directories on your computer (local). 

Your root directory is usually in a folder labeled www or public_html, but it might use a different name. If you aren’t sure what folder to look in, ask your hosting provider. You’ll know you’re in the correct folder if you see the wp-admin, wp-content, and wp-includes folders near the top of your file list.

Step 5: Navigate to functions.php in WordPress core, your parent theme, or child theme. If you’re looking for functions.php in WordPress core, you’ll navigate to the wp-includes folder.

If you’re looking for functions.php in your theme directory, you’ll navigate to wp-content → themes → yourtheme.

To find your child theme’s functions.php file, go to wp-content → themes → yourtheme-child.

Step 6: Download functions.php. Now that you know where functions.php is located and have accessed it, you might want to inspect or edit the file. Before you can do that, you’ll need to download it. Right click on your functions.php file and select Download. Your file will be downloaded to your local machine.

Accessing functions.php in cPanel

If your host uses cPanel, you can access functions.php through its file manager. If you don’t know how to find cPanel in your host’s dashboard, contact their customer support for help. 

Step 1: Open cPanel’s File Manager. Once you’re in cPanel, navigate to the Files section and click on File Manager.

Step 2: Open your website’s root folder. The root folder is commonly called www or public_html, but it may have another name. Root folder naming conventions differ on some hosts, so if you aren’t sure what folder to look in, ask your hosting provider. 

You’ll know you’re in the correct folder if you see the wp-admin, wp-content, and wp-includes folders near the top of your file list.

Step 3: Find and download functions.php. The functions.php file for WordPress core is located in your wp-includes folder. 

Your theme’s functions.php file is located in wp-content → themes → yourtheme.

If you’re looking for your child theme’s functions.php file, you can find it in wp-content → themes → yourtheme-child.

When you’ve found the functions.php file you’re looking for, right click on functions.php and click Download, or single-click functions.php and then click the Download option from the top menu.

If you rename your file when you save it, make sure to name it back to functions.php before re-uploading it. And before you make changes to and overwrite functions.php, back up your WordPress site. 

When should I edit functions.php in WordPress?

Before we dive in to how to edit functions.php, we should talk about if and when you should edit it. There are many reasons you might want to edit PHP code in WordPress, but adding that code to your functions.php file is not always the best option and should only be done under certain circumstances, which we’ll discuss below.

When to edit functions.php in WordPress core

Never. You shouldn’t edit functions.php in WordPress core. At most, you might replace it if you find that it’s been corrupted, but deleting or adding code to WordPress core functions.php is likely to break your site. So, you can open it, inspect it, replace it with a fresh copy if you need to, but don’t mess around on any live websites.

When to edit functions.php in your theme

When it comes to your theme’s functions.php file, you may or may not need to edit it. If you’re creating your own theme, you’ll most certainly want to add some custom code to functions.php. Just about every theme has code in its functions.php file that gives it a unique set of features and capabilities. Besides your stylesheets, these functions are a huge part of what makes one theme different from another.

If you’re adding code to your theme’s functions.php file that isn’t specific to your theme and could be used independently of your theme, consider making it a plugin instead. This way you can use that feature across multiple themes and even submit it to the WordPress.org plugin library where it might benefit other WordPress users. 

Before creating your plugin, check the plugin library to make sure what you’re creating doesn’t already exist. If a quality solution exists already, you might want to save your development energy for a different custom feature on your site.

When to edit functions.php in your child theme

If you’re using a theme from a developer, and want to modify the functions.php file, you should always use a child theme to make those changes. When theme developers issue a new version of their theme and you update to the latest one, your current theme is overwritten by the new files — including functions.php. 

Child themes are unaffected by parent theme updates, so you’ll retain all your custom code if you make changes in a child theme’s functions.php file.

Before adding code, consider whether using a plugin would be a better solution. Is the code you’re adding specific to your theme? Edit your child theme’s functions.php file. Is the code you’re adding something you want to still have if you change themes in the future (e.g. Google Analytics tracking code or Facebook pixel)? Use a plugin.

How to edit functions.php in WordPress

You should always take steps to protect your site from any mistakes you might make while editing functions.php. So before you start making edits, back up your site and consider creating a staging site to test them first. This way your live site is not disrupted if you accidentally add some code to functions.php that causes major issues or — even worse — crashes your site completely.

Now that you’ve backed up your site, you can move on to editing your functions.php file.

How to edit functions.php in the WordPress Theme File Editor

Editing functions.php in the WordPress Theme File Editor is a little risky. If you’re using this tool because you don’t have access to cPanel or SFTP, then you’ll be in a pretty bad situation if your edits cause a fatal error that prevents you from accessing your WordPress dashboard. 

If you want to edit functions.php in the Theme File Editor, make sure that you have direct access to the server and your backups so you can restore your backup file quickly.

You can find the WordPress Theme File Editor under Appearance → Theme File Editor in your WordPress admin panel. 

You’ll be taken to the Edit Themes screen, where you should select your child theme, then select the functions.php file from the Theme Files column at the right of your screen.

If you’ve selected the parent theme instead, you’ll see a warning at the bottom of your screen that says, “Caution: This is a file in your current parent theme.” You don’t want to make edits to your parent theme’s functions.php file because your changes will be overwritten the next time you update your theme.

If you see functions in your file that you don’t understand, WordPress includes a handy documentation lookup feature just above the Update File button. Click the dropdown and search for the function name that you want to learn more about and click Look Up. You’ll be directed to the WordPress.org documentation for that function. 

When you’re done with your changes, click Update File. Check the front and back end of your site to make sure everything is still working as intended. If you encounter a fatal error and need to restore functions.php from your backup, you can do that in cPanel or via SFTP.

Editing functions.php with a text editor

The best way to edit functions.php is in your code editing software of choice. Since you’re editing a copy that’s offline on your local computer, you don’t have to be connected to the internet to work on your file. You’ll also have more control over when you commit your changes to your live site. 

You can edit your code whenever you like and upload your changes at a time when your website normally gets the least traffic. That way, if there are any issues, the fewest number of visitors will be impacted.

Step 1: Open functions.php in your text editor. If you aren’t familiar with using a text editor, there are several free options to choose from. 

Free source code and plain text editors:

Application	System
Notepad++	Windows
Atom.io	Windows, Mac, Linux
Sublime	Windows, Mac, Linux
TextEdit *make sure you’re in plain text mode	Mac (default application)
Notepad	Windows (default application)

Step 2: Edit functions.php and save to your local machine. Your display may look different depending on what program you use to edit your functions.php file. This is what PHP code looks like in atom.io:

Add or change whatever information you need to, then save your file. 

Step 3: Log into your web server via SFTP or cPanel. Navigate to your theme or child theme folder and find the functions.php file.

Step 4: Change the file name of functions.php on your web server. In case your edited version contains errors, you don’t want to overwrite your original functions.php file. You’ve made a backup, of course, but instead of having to pull the functions.php file from your backup, you’ll have your original file on-hand. 

You want to be able to restore the functions.php file quickly if something goes wrong, so renaming it to something like ‘functions-orginal.php’ will make sure that the contents of the original file are preserved on your server.

Step 5: Upload functions.php from your local machine to your webserver. Using SFTP or cPanel, upload your functions.php file to your theme or child theme’s main directory.

Step 6: Visit your website to make sure it’s working correctly. Once you’ve uploaded your functions.php file, you should check to make sure that everything is working on your site. Visit the front end and log in to the WordPress dashboard to make sure everything is accessible and displays and functions correctly. 

Step 7: Delete the old, renamed functions.php file. Once you’ve established that your site is working properly, you can delete functions-original.php (or whatever you renamed it to). If you find an issue down the road, you should still have your functions.php file from the backup you made.

Editing functions.php directly in cPanel

If you don’t have or don’t want to use a source code editor, you can edit functions.php directly in cPanel (if your host uses cPanel). Like editing in the WordPress Theme File Editor, it’s a little more risky than working on your local machine. If your internet connection is disrupted while you’re editing, you could lose your changes. You also run the risk of potentially overwriting your original functions.php file.

Step 1: Find functions.php in cPanel. In cPanel, click on File Manager.

Navigate to your root folder (usually public_html or www, but it could have a different name).

Step 2: Make a copy of functions.php. In your File Manager main menu, click + Folder to add a new folder. You’ll want to make a copy of your functions.php file and save it here as a backup.

Name your new folder something easy to identify like ‘backup functions’ so you can easily find it later. Click Create New Folder.

Step 3: Find functions.php in your theme or child theme folder and copy it to the backup folder. In your theme or child theme folder, scroll down to functions.php and right click on the file name. Select Copy.

A dialog box will appear asking you to enter the path you want to copy the file to. The path to the folder you’re currently in will be pre-populated, so if the file path to your backup folder differs from what you see, type in the correct path. Click Copy File(s).

Step 4: Navigate back to functions.php in the theme or child theme directory. Now that you have a backup, you can go back to the functions.php file in the theme or child theme directory and start editing. 

Right click on functions.php, then click Edit.

Step 5: Edit functions.php. You should now see the contents of your functions.php file on your screen. It should look something like this: 

Add or change whatever information you need, then save your file. 

Using a plugin to add functions to your WordPress site

Instead of directly modifying the functions.php file, you can use a plugin like Code Snippets to add functions to your website. If you need to add a fair number of functions to your site, it can be easy to lose track of which functions you still need and which you don’t. 

Code Snippets provides a graphical user interface (GUI) for managing your blocks of PHP code. You can add descriptions so that you know what the code is supposed to do, and turn blocks of code on and off, much like activating and deactivating a plugin.

Since you’re not making changes to functions.php, it’s a much safer method of adding PHP functions to your WordPress site.

How to protect functions.php from security exploits

The functions.php file is often a target of hackers, so keeping it safe should be a high priority. Take the following steps to help you secure your functions.php file:

1. Install a security plugin

By using a security plugin, you’ll enjoy advanced protection from hackers across multiple areas of your site. 

Jetpack Security is an inexpensive option that helps keep your site safe from malicious attacks. It includes malware scanning and one-click fixes, brute force attack protection, downtime monitoring, an activity log so you know if and when your site was hacked, and login protection via two-factor authentication (2FA).

Jetpack Security also monitors your site for any changes to core WordPress files, outdated or insecure plugins, and other vulnerabilities so that you can catch them before a hacker finds them and takes advantage. 

Plus, it provides real-time WordPress backups so you can quickly restore a clean version if anything goes wrong — even if you can’t log into your site.

2. Deny access to WordPress core functions.php via the .htaccess file

If your website is hosted on an Apache server, you can use an .htaccess file to help protect your WordPress core functions.php file by blocking access to the entire wp-includes folder.

Step 1: Download .htaccess

Using SFTP or cPanel, navigate to the root folder of your website. Right click on .htaccess and select Download to download the file to your local computer.

Step 2: Add code to block access to the wp-includes folder

In a source code or plain text editor, open .htaccess and add the following code:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^wp-admin/includes/ - [F,L]
RewriteRule !^wp-includes/ - [S=3]
RewriteRule ^wp-includes/[^/]+\.php$ - [F,L]
RewriteRule ^wp-includes/js/tinymce/langs/.+\.php - [F,L]
RewriteRule ^wp-includes/theme-compat/ - [F,L]
</IfModule>

Save your file. Make sure that your editor program does not include a file extension. If you’re using Notepad++ or Text Edit, it may add a .txt file extension. The file should simply be named ‘.htaccess.’ 

Step 3: Upload the edited .htaccess back to the root folder

Upload your edited .htaccess file back to your website’s root folder. You’ll be asked if you want to overwrite the existing file. Click Ok.

Now your .htaccess file should block external access to any files in your wp-includes folder, including functions.php.

3. Deny access to functions.php using functions.php

You can block direct access to your functions.php file by adding the following code snippet directly to functions.php.

if (!empty($_SERVER[‘SCRIPT_FILENAME’]) && ‘functions.php’ ==
basename($_SERVER[‘SCRIPT_FILENAME’]))
{
die (‘Access denied!’);
}

4. Hide functions.php outside of the root directory

Hackers know the default location of all standard WordPress files. Changing the location of sensitive files to a restricted access folder outside the root directory can keep it out of reach of hackers. This process is a little more involved than just adding some code to your .htaccess file, but it’s worth the extra effort for the additional layer of protection to your website. 

In just a few steps, you can secure functions.php outside of the root folder.

Step 1 : Download your current functions.php file

If you’re moving your theme’s functions.php file, you’ll find it under wp-content → themes → yourtheme. Your child theme’s file will be in wp-content → themes → yourtheme-child.

Once you’ve found your functions.php file, download it to your computer via SFTP or cPanel.

Step 2 : Create a new directory outside of the root folder

Navigate outside of your root directory to the next file folder level up. You should see the name of your root folder as well as several other folders. In this directory, right click and select Create directory.

Give your directory a name that’s easy to remember as the location of your functions.php file.

Step 3: Upload functions.php to your new folder

Upload the functions.php file you downloaded earlier into your new folder via SFTP or cPanel. 

Check your new folder and functions.php file permissions and make sure they’re set to 600.

Step 4 : Point WordPress to the new functions.php file

You should have a functions.php file in your new directory as well as the original functions.php file that is still in your theme folder. In order for WordPress to find and use the correct file, you’ll want to delete all the information in your theme file’s functions.php file and the following code snippet:

<?php
include('/home3/usr/securefunctions/functions.php');
?>

Note: Your file path will look different, as you’ll be using your server’s directory names.

In cPanel, you can open the root directory’s functions.php file and edit it directly or you can edit the copy you downloaded to your local machine earlier using a source code editor. For this example, we’ve edited the copy we downloaded earlier using Atom.io.

Save your funtions.php file and upload it back to your theme directory.

You’ll be asked if you want to overwrite the file. Click Ok.

Now, WordPress should reference your new functions.php file in its secure location outside of the root folder.

4. Change the name of your functions.php file

Changing the name of your functions.php file is another step you can take to keep it safe from hackers. You’ll need to host this file outside of your root folder, so if you’ve followed the process in Hide functions.php outside of the root directory, you’ll only need to take a few additional steps.

Step 1: In your secure directory outside the root folder, change the file name of functions.php

Go to the functions.php folder hosted outside of your root directory and change the file name to something unique, like ‘keep-out.php’ or ‘these-are-not-the-functions-you-are-looking-for.php’. Okay, that last one’s a little long, but it doesn’t really matter what you call it as long as you include it in the file path in the theme folder copy of functions.php.

Step 2: Edit the code in functions.php in your root directory to reflect the name change

Now that you’ve changed the name to something other than functions.php, you’ll need to make sure your theme directory copy of functions.php is pointing to the right file name. 

Download the root folder copy of functions.php to your local computer and edit it with your text editor. Change the functions.php file name to your new file name, then save your file.

<?php
include('/home3/usr/secureconfig/keep-out.php');
?>

Step 3: Upload functions.php back to the theme directory

You’ll be asked if you want to overwrite the existing file. Click Ok. 

Now WordPress should point to your renamed functions file. 

Additional layers of security for functions.php

You can add some additional protection to your website as a whole, including your functions.php file, by making similar changes to your wp-config file like renaming it, hosting it outside the root directory, and denying public access.

If you see suspicious code in your functions.php files and are worried you may have been hacked already, you’ll want to read up on how to detect and remove malware from your WordPress website.

What code can I add to functions.php in WordPress?

There are a lot of different code snippets that you can add to your WordPress functions.php file. However, you’re often better served by using a plugin (or writing your own plugin) for many functions. If the code you want to add is specific to your theme, then you can add that PHP code to your child theme’s functions.php file. 

Below are a handful of useful functions you might insert into your child theme’s functions.php file: 

Adding a new admin user in functions.php

If you’ve lost admin access to your WordPress dashboard and can’t recover your username or password via email, you can create a new admin user through your hosting account. Either via SFTP or cPanel, you can download your functions.php file and add the following code to create a new admin user for your site.

function qode_add_new_admin_account() {
$user = 'your-username';
$password = 'your-password';
$email = 'your-email';
if ( ! username_exists( $user ) && ! email_exists( $email ) ) {
$user_id = wp_create_user( $user, $password, $email );
$user = new WP_User( $user_id );
$user->set_role( 'administrator' );
}
}
add_action( 'init', 'qode_add_new_admin_account' );

In the above code, replace ‘your-username’, ‘your-password’, and ‘your-email’ with your own credentials. Save your functions.php file and re-upload it to your theme folder. This will create a new admin user with the username, password, and email address that you’ve assigned in the code. 

After you’ve uploaded your file, navigate to your site’s login page and use your new username and password to log in. Once your login is successful and you’ve confirmed that you have admin privileges, you should remove the code that you added to create your new admin account from functions.php. 

Adding and removing image sizes in functions.php

When you upload an image to the WordPress Media Library, multiple variations of your image are generated. WordPress has default thumbnail, small, medium, and large sizes that are used in addition to your full size image. Your theme will generally pull the optimal image size for individual parts of your site. 

If you’re creating your own theme or need to make modifications to a child theme to accommodate additional custom image sizes, you can do so in your functions.php file. 

Use the following code and change your custom image size name from ‘custom-small-square’ and ‘custom-landscape’ to whatever name you’d like to use. The numbers next to your custom image size name represent the image size in pixels, so enter the pixel values with width first and height second.

function register_custom_image_sizes() {
if ( ! current_theme_supports( 'post-thumbnails' ) ) {
add_theme_support( 'post-thumbnails' );
}
add_image_size( 'custom-small-square', 450, 450, true );
add_image_size( 'custom-landscape', 1000, 600 );
}
add_action( 'after_setup_theme', 'register_custom_image_sizes' );

Keep in mind that additional custom image sizes can weigh down your site and impact load times. If you have some WordPress default image sizes that your theme doesn’t use, you may want to delete and disable those to make room for your custom sizes. 

If you want to disable WordPress default image sizes, you can place this code snippet into your functions.php file:

add_filter( 'intermediate_image_sizes_advanced', 'prefix_remove_default_images' );
// This will remove the small, medium, and large default image sizes. 
function prefix_remove_default_images( $sizes ) {
 unset( $sizes['small']); // 150px
 unset( $sizes['medium']); // 300px
 unset( $sizes['large']); // 1024px


 return $sizes;
}

If you only need to disable one or two sizes, you can only add those sizes to the code above and delete the code that you don’t need. 

Use functions.php to allow additional file types in uploads

WordPress only allows a few different file types to be uploaded in your WordPress dashboard. This is a reasonable security measure, but you might encounter a situation where you need to upload a file type that’s not natively allowed. 

To add more allowed file types to WordPress, add the following code to your child theme’s functions.php:

function additional_upload_file_types($mime_types){
$mime_types['stl''] = 'application/sla';
$mime_types['stl'] = 'application/vnd.ms-pki.stl';
$mime_types['stl'] = 'application/x-navistyle';
return $mime_types;
}
add_filter('upload_mimes', 'additional_upload_file_types', 1, 1);

For the above example, we used the stl file type, which is a CAD file type. It’s an unusual file type to upload to a website outside of certain niche industries, but if your site is for an industrial designer, engineering firm, or even an orthodontics lab, you might find the ability to upload STL files really useful. 

You can replace the $mime_type variable with whatever file extension suits the needs of your website. You’ll also need to include the media type and subtype after that (e.g. ‘application/sla’ or ‘image/octet-stream’). Here’s a complete list of mime types that you can refer to. 

Frequently asked questions about editing the functions.php file in WordPress

We’ve covered what the functions.php file is, how to find functions.php, how to access it, how to edit it, and a few code snippets you can add to your functions.php file. We’ll wrap things up with a few helpful answers to frequently asked questions. 

Do I really need to use a child theme to edit functions.php?

The short answer? Yes.

If you’re a theme developer, you’ll definitely want to add your theme-specific functions directly to your theme’s functions.php file. If you’re modifying a theme from another developer that will get regular updates, however, you’ll absolutely want to use functions.php within a child theme. 

Most theme developers will periodically make updates to their themes for security and performance reasons, or to add new features. If you change the parent theme’s functions.php file, those changes will all be overwritten when you update to your theme’s latest version. All your hard work and customizations — poof! Gone. 

Child themes aren’t touched when the parent theme updates, so if you make changes to your child theme’s functions.php file, your changes will be preserved any time you update your parent theme.

I edited functions.php and now I don’t have access to my WordPress dashboard. Help! 

In the unfortunate event that you edited the functions.php file and caused a critical error on your site that kept you from accessing the WordPress dashboard, don’t worry — all is not lost!

There are a few things you can do to restore access to your site. You can edit functions.php via SFTP and a text editor or directly in cPanel if you know which bit of code caused the issue. Alternatively, you can restore functions.php from a backup or download a fresh copy of functions.php from your theme developer. 

I know what code I messed up. I just need to access and edit functions.php to fix it.

See How to edit functions.php above for instructions on how to access and edit your theme or child theme’s functions.php file.

I have no clue what I did to my functions.php file, but I have a backup.

If you have a backup on hand, you can access your files either on your web host’s server or your remote server (depending on where you have opted to store these files), and use them to replace your corrupt functions.php file via SFTP or cPanel. 

If you feel more comfortable restoring your entire site backup rather than trying to restore just the functions.php file, our article, “How to Restore WordPress from a Backup” goes in depth on the different methods you can use to restore your WordPress site.

I have no idea what code caused the problem and I didn’t make a backup.

If you don’t have a backup, you can download a fresh copy of the theme you’re using from your theme developer, extract the functions.php file, and overwrite the broken functions.php file on your server via SFTP or cPanel.

Note: If you’re using a theme that hasn’t been updated in awhile, you may encounter issues in overwriting functions.php with a version that’s from a much more recent update. If you encounter issues, you might be better off just manually updating your entire theme to the latest version. Alternatively, you can contact your theme developer to get the theme files for your current version and use that version of functions.php.

Can I add JavaScript to my functions.php file?

Yes, you can add code to your functions.php file that will add your custom JavaScript to either specific pages, posts, or all pages and posts on your site. This article covers all the different ways you can add JavaScript to your functions.php file.