Update Core

What is Update Core in WordPress?

Updating the WordPress core means replacing the main software files of a WordPress site with the latest version. This includes key files from WordPress.org that are required for the site to run. Updates add security patches, bug fixes, and feature improvements. You can do this through the WordPress admin dashboard or manually if needed.

How Core Updates Work

When a new version of WordPress is released, a notification appears in the admin dashboard. It usually shows up at the top or in Dashboard > Updates. To update, click the “Update Now” button. WordPress will download new files, install them, and make any necessary changes to the database.

During this process, WordPress creates a .maintenance file. This temporarily shows a maintenance message to visitors until the update finishes. The file is removed automatically once the update completes. If not, you can delete it manually using an FTP client.

Types of Updates

WordPress supports both manual and automatic updates. By default, minor and security updates are installed on their own. Starting from version 3.7, this is built into the core. For full version upgrades and plugin or theme updates, users can allow automation by editing the wp-config.php file. You can control this with constants like WP_AUTO_UPDATE_CORE or by using filters in a custom plugin.

Manual Update Method

If the automatic or one-click update fails, you can update WordPress manually with these steps:

1. Download the latest zip package from WordPress.org.
2. Use an FTP client to connect to your site’s root directory.
3. Replace all folders except wp-content. Do not overwrite wp-config.php, custom .htaccess, or the wp-content folder.
4. Visit /wp-admin/upgrade.php if prompted, to complete any database changes.

Manual updates help when server setups prevent the auto method or when permissions require ownership by a different user.

File Ownership and Permissions

WordPress determines how to perform updates based on file system permissions. If your server runs under a user that does not own the WordPress files, WordPress will ask for FTP credentials. Updates may fail when permissions are incorrect. Misconfigured file ownership can trigger connection errors or cause updates to hang.

Site Customization and Update Impact

Core updates remove and replace main system files. Any custom edits made directly to WordPress core files will be erased. To retain custom functionality, use a child theme or place custom code in your theme’s functions.php file or in a site-specific plugin instead of editing core files.

The wp-content directory, which includes themes and plugins, remains untouched by the core update. However, it’s always good to back up this directory before running updates.

Security and Stability Considerations

Running the latest WordPress version helps prevent attacks and bugs. Many known issues and vulnerabilities are fixed through updates. For example, many hacked WordPress sites are found running outdated core versions, often paired with old plugins or themes.

Updates also keep your site working with newer versions of PHP or server software. This avoids compatibility issues and unexpected errors.

Common Update Issues

• FTP Prompt During Update: This often happens when file permissions don’t allow direct file access. Updating manually may be required.
• Stuck in Maintenance Mode: If your site stays down after an update, delete the .maintenance file from the site root.
• Loss of Custom Code: Editing core files directly will cause your changes to be removed. Instead, use proper override methods within themes or plugins.

Automatic Core Updates

Security and maintenance releases are applied automatically by default. For others, you can adjust the behavior:

• To turn off all core updates:
  define( ‘WP_AUTO_UPDATE_CORE’, false );
  
• To allow only minor updates:
  define( ‘WP_AUTO_UPDATE_CORE’, ‘minor’ );
  
• To enable all core updates, including major releases:
  define( ‘WP_AUTO_UPDATE_CORE’, true );
  

These settings go in wp-config.php. More fine-grained control is possible using the automatic_updater_disabled or allow_major_auto_core_updates filters.

Backup and Compatibility Tips

Before updating:

• Back up your site files and database.
• Disable plugins temporarily. Re-enable them one at a time after the update to spot issues.
• Use a staging site if you run a complex WordPress installation.

These steps reduce risk during updates, and help identify broken plugins or template conflicts.

Database Updates

Sometimes, updates modify database tables. After updating files, WordPress may prompt you to run a database upgrade by visiting a special admin URL like:
http://yoursite.com/wp-admin/upgrade.php

If you skip this step, parts of the site might not work correctly. Always follow through when prompted.

Summary of Core Files

Core updates replace standard WordPress directories such as:

• /wp-admin/
• /wp-includes/
• Root-level files like index.php, xmlrpc.php, etc.

The wp-content folder is preserved. Installed themes and plugins are not affected unless they are directly modified or manually deleted.

By keeping the core updated, administrators reduce security risks and avoid software conflicts.