How to Fix REST API / AJAX Errors in WordPress: A Complete Guide

Running a WordPress website can be exciting, but sometimes small errors stop your site from working the way it should. One common problem many site owners face is REST API or AJAX errors. These errors can affect plugins, themes, and features that depend on smooth communication between your website and the server.

If you own a website like SmartLifeSol.com, it’s important to understand why these issues happen and how you can fix them without losing your mind.

What is the REST API in WordPress?

The REST API in WordPress allows your website to communicate with other applications. For example, when you use the block editor (Gutenberg) or a plugin that fetches live data, it relies on the REST API.

If the REST API is not working correctly, features like:

• Theme customization preview

• Plugin updates

• Block editor functions

• Contact forms
  may stop working.

What is AJAX in WordPress?

AJAX (Asynchronous JavaScript and XML) helps your website load data without refreshing the entire page. You see it in action when:

• Submitting a form without reloading the page

• Adding items to a shopping cart

• Loading posts with “Load More” buttons

If AJAX errors occur, these dynamic functions break, and your website feels incomplete.

Why Do REST API and AJAX Errors Happen?

There are several reasons why WordPress websites face these errors:

1. Plugin Conflicts – Some plugins block or override REST API requests.

2. Theme Issues – Poorly coded themes may interfere with AJAX.

3. SSL/HTTPS Misconfigurations – Wrong SSL setup can block requests.

4. Firewall or Security Plugins – Sometimes these plugins mistakenly block REST API calls.

5. Server Configuration – Issues with .htaccess, PHP limits, or mod_security rules.

6. Caching Problems – Over-aggressive caching can block live requests.

How to Fix REST API / AJAX Errors in WordPress

Here are some practical ways you can fix the issue:

1. Check Site Health

• Go to Tools → Site Health in your WordPress dashboard.

• It will show REST API and AJAX-related problems with possible fixes.

2. Disable Problematic Plugins

• Deactivate all plugins.

• Reactivate them one by one to find which plugin is causing conflicts.

3. Switch to a Default Theme

• Change your theme to a default one like Twenty Twenty-Five.

• If the error is gone, your theme is the problem.

4. Fix SSL and HTTPS Issues

• Ensure your site URL in Settings → General starts with https://.

• Use a plugin like Really Simple SSL to fix HTTPS conflicts.

5. Check Security or Firewall Settings

• If you use plugins like Wordfence or server firewalls, check if they are blocking requests.

6. Review .htaccess File

• Reset your .htaccess file to default WordPress rules.

• Go to Settings → Permalinks and click Save to refresh rewrite rules.

7. Increase PHP Memory Limit

• Add this line to your wp-config.php file:

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


8. Contact Hosting Provider

If none of the above works, ask your hosting provider to check server logs and configuration.

Final Thoughts

REST API and AJAX errors can be frustrating, especially when you depend on plugins and themes for your website features. The good news is that most of these issues can be fixed by checking plugins, themes, SSL, or server settings.

If you want a smooth and professional website experience, take care of these technical details or hire an expert. At the end of the day, your website visitors want a fast, functional, and reliable experience—and solving these errors is a big step toward that.

For more helpful guides, visit SmartLifeSol.com and keep your website running at its best.