Using Your Browser to Diagnose JavaScript Errors

Interactive functionality in WordPress often relies on JavaScript. If you encounter broken menus, metaboxes that won’t drag, or buttons that don’t work (such as Add Media), these may be caused by JavaScript errors or conflicts.

This guide explains how to use your browser to diagnose JavaScript issues so you can provide better information when requesting support.

Step 1: Try Another Browser

Different browsers sometimes handle JavaScript differently. Test your site in at least two browsers:

• If the issue only occurs in one browser → it may be browser‑specific (e.g., an extension conflict).
• If the issue occurs in all browsers → it is likely a JavaScript or plugin/theme error.

Note: Browser extensions (ad blockers, privacy tools) can sometimes interfere with JavaScript. Try disabling extensions or using a private/incognito window to rule this out.

Record which browsers show the error; include this information in your support request.

Step 2: Enable SCRIPT_DEBUG

WordPress uses minified JavaScript by default. Enabling script debugging forces WordPress to load the full, uncompressed versions, which makes errors easier to trace.

1. Reload your site and check if the error still occurs.

• If the issue is fixed → turn off SCRIPT_DEBUG again and report this detail in your support request.
• If the issue persists → continue to Step 3.

Step 3: Open Browser Developer Tools

Every modern browser includes Developer Tools. Open them and switch to the Console tab.

• Chrome / Edge / Opera: Press F12 (or Ctrl+Shift+I / Cmd+Option+I) → select the Console tab.
• Firefox: Press F12 (or Ctrl+Shift+K / Cmd+Option+K) → Console tab.
• Safari: First enable the Develop menu: Safari → Settings → Advanced → Show Develop menu. Some versions of Safari provide the option at Safari → Settings → Advanced → Show features for web developer. Then open Develop → Show JavaScript Console, or press Cmd+Option+I.

Step 4: Identify the Error

Errors will appear in the Console. A typical error message might look like:

Tips:
– Copy the full error message and stack trace (not just the line number).
– If no errors appear, reload the page — some only occur on load.
– Note the file name and line number of the error (e.g., jquery.js:2).

Step 5: Report the Issue

When requesting help, provide as much detail as possible. Go to the WordPress.org Support Forums or the plugin/theme’s dedicated forum:
– Plugins: https://wordpress.org/support/plugin/PLUGINNAME`
- Themes:https://wordpress.org/support/theme/THEMENAME`

Include the following information:
– Browsers where the error occurs
– Whether enabling SCRIPT_DEBUG changed the behavior
– The full JavaScript error message (including stack trace)
– File name and line number where the error occurred
– Context — what action triggered the error
– A link to the affected page, if possible

Summary

By confirming the issue across browsers, enabling SCRIPT_DEBUG, and checking the browser console, you can quickly diagnose JavaScript errors. Sharing this information in support requests makes it much easier for volunteers and developers to help resolve your problem.