In typical scenarios, users don’t need to change core files in WordPress. However, in the case of inserting specific functionalities in the WordPress backend, then this is when should you edit core WordPress files.

In this article, you’re going to learn about WordPress core files. You will also know when you should make changes to core files in WordPress.

Introduction to Core Files in WordPress

The default files supplied with the WordPress package are referred to as core files in WordPress. The purpose of core files in WordPress is to maintain WordPress functionality properly.

For example, once you’ve downloaded and extracted the WordPress package from its official resource, the files, directories, or media you see under the “WordPress” folder fall under the WordPress core files, such as the wp-content directory or wp-config.php file.

When should you edit Core WordPress Files

Note: Remember to take your site’s backup before editing the WordPress core files. To proceed, you don’t need to use additional code editors. The WordPress default file editor in the dashboard is enough for the said purpose.

To keep WordPress running smoothly, users are always recommended to keep WordPress core files the same. However, if you have no option, you can change the WordPress core files in the following scenarios.

Do minor changes without WordPress plugins

WordPress core files are sensitive to code scripts, such as the wp-config.php holds information about your site’s database, usernames, and passwords to login.

In case you don’t prefer separate plugins for minor tasks, such as forcing SSL admin and HTTPs redirects, you can make changes to core files in WordPress.

Let’s describe an example of the WordPress core files in this case. Placing the define(‘FORCE_SSL_ADMIN’, true); in wp-config.php will set the WordPress Admin dashboard load with HTTPS.

Keep changes after WordPress updates

Now, as you keep making changes for minor tweaks in WordPress, you’ll need to make changes again if you’ve updated the WordPress package from the dashboard. This happens when a new update for the WordPress core package rolls out.

In this case, updating WordPress wipes out custom edits from the core files. In this scenario, you’ll need to make changes in the WordPress core files – again and keep small changes as you were using them before WordPress updation.

Improvements in WordPress default functionality

Editing core files in WordPress to increase WordPress performance often refers to as WordPress Tweaks and is performed by placing, editing, or changing code snippets in the core files.

For example, placing define(‘WP_POST_REVISIONS,’ 10 ); in wp-config.php limits post revisions for pages and posts. Post revisions are “record entries” made in the database after users update a post or page in WordPress editor.

Similarly, you’re curious to increase WordPress performance without plugins. In that case, you can add more snippets to core files in WordPress, such as post-auto-save intervals, error log management, and setting up a cookie domain.

Note: There is a difference between WordPress Tweaks and minor changes. By editing the WP core files, WordPress Tweaks address significant concepts, such as dealing with post revisions, auto-save posts, or changing the login page’s URL. On the other hand, small changes usually deal with small wins, such as HTTPS redirects or making changes to specific directories in WordPress.

Website performance, security, and recovery

In WordPress, the installation, removal, and management of plugins affect the WordPress default, base, or core files.

For example, WordFence – a plug-in for WordPress security, needs to change the htaccess file to configure its web application firewall. If you’ve planned to migrate your site to a new host, change your site’s DNS information, or re-install WordPress from scratch, you will also need to handle core files in WordPress.

In such scenarios, we have personally experienced assistance from hosting customer support. In simple words, when making changes to core files depends on external agents, WordFence, in this case, you will need to re-change the WordPress core files and regain the previous performance – such as htaccess in the above example.

In the same manner, editing the WordPress default files is associated with website security, too. For example, you will need to change WordPress core files if you need to hide your site’s login page from hackers. It helps you avoid brute force attacks, which involves trying out password combinations to find a good set of login credential on the victim site.

Third-party apps integration with WordPress

There are cases when you need to change your site’s core files. For example, if you aim to build a PaaS environment, you may need to change the WordPress core files.

Note: Product as a Service (PaaS) refers to a web application used for a specific purpose, such as file conversions or email marketing tools. In case you are passionate about building one, in addition to WordPress integration, you will need to make changes to the core files in WordPress. A PaaS application is usually accessed through the web.

In the same manner, you can’t assume your theme, plugin, or custom code will work without integration with core files in WordPress. The said case is experienced mainly by WordPress developers.

To be clear, let’s describe the example of editing core files with WordPress plugins.

Once you’ve installed a plugin for redirects, new entries of redirects can be seen in the WordPress htaccess file. As a WordPress developer, this shows an example of how, when, and why you may need to change the WordPress essential files to adjust programming capabilities.

Similarly, WordPress core files need to be changed for manual development and 3rd party app integration. For example, you can integrate Google Analytics and Search Console with a WordPress plugin called Monster Insights; however, editing WordPress core files (header.php) will make a difference with ease manually without using a plugin for Google integration.

WordPress website under development

Editing the WordPress (index.php) file will put your site in maintenance mode.

If you want to go offline for a moment, you can change the index file inside your site’s WordPress directory. Here, index.php is one of the most sensitive files of WordPress and is used to let browsers show a site’s home page in most cases.

Here, by renaming a WordPress site’s index.php file, you can make the whole place go offline until you have made changes. Once done, you can re-change the index.php file’s name to the original.

Website maintenance mode is achievable by changing the WordPress core files without installing a separate plugin.

Custom case

A custom case involves changing a specific part of the WordPress interface, functionality, or behavior. This phase falls under the core development of WordPress by official contributors.

For example, instead of Classic Editor, the WordPress new versions come with the Gutenberg Block Editor for posts and pages.

If changing the WordPress editor is the WordPress’ next version for developers, editing the core files in WordPress is the only option to proceed with WordPress core up-gradation.

Similarly, you may have noticed custom interfaces from users who prefer personal branding, such as placing custom logos on login pages, changing the admin’s dashboard colors, or redirecting to a page after a user has logged in successfully. Such maneuvers fall under the custom approach to editing the core files in WordPress for branding purposes.

Final words

Editing WordPress’ core files indicate special conditions to improve, change, or make a difference in WordPress functionality.

However, you can change the core files if you’re skilled enough. Otherwise, changing the WordPress default files may damage your site.

In this write-up, we addressed different scenarios when you will be editing your site’s core files in WordPress. Once you’re ready to proceed, remember to take your site’s backup first.

For more information on changing core files in WordPress, performance, or site migration and recovery, you can let us know your thoughts. We’d love to help you sort things out for improved performance, SEO rankings, or error handling in WordPress.