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Understanding Chrome Extension Files in Developer Tools: What is installHook.js?

Learn what installHook.js is, why it appears in Chrome Developer Tools, and how to identify and disable the browser extension responsible for it.

Mellowtel Team

Mellowtel Team

🧩 Understanding Chrome Extension Files in Developer Tools: What is installHook.js?

Have you ever noticed unfamiliar files appearing in your Chrome Developer Tools while working on web projects? You're not alone. Many developers—especially those using React—have encountered a file called installHook.js. Let's explore its origins and how to get rid of it if needed.

đź“„ What is installHook.js?

installHook.js is a file commonly associated with the React Developer Tools Chrome extension. It's not part of your actual project code, but is injected by the extension to enhance the React development experience.

🔍 Key Points About installHook.js:

  • Origin: It's loaded by the React Developer Tools extension, not your website.
  • Purpose: Helps set up the development environment for React applications.
  • Impact: Does not affect your application’s performance for end users.
  • Visibility: Only appears in Developer Tools, never in production builds.

🛠️ How to Identify and Deactivate the Responsible Extension

If you're seeing unfamiliar files in Developer Tools, here’s how to trace and disable the responsible extension:

1. Identify the File

  • Open Chrome Developer Tools (F12 or Right-click > Inspect).
  • Go to the Network tab.
  • Refresh the page and locate the file (e.g., installHook.js).

2. Check the File URL

  • Click the file in the Network tab.
  • Look at the Request URL.
  • If it starts with chrome-extension://, it's injected by an extension.

3. Note the Extension ID

Example URL:

chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/installHook.js

The string after chrome-extension:// is the extension ID.

4. Find the Extension

  • Visit chrome://extensions/
  • Use the search bar to paste the extension ID.
  • Chrome will show the matching extension.

5. Deactivate or Remove

  • To disable: Toggle off the switch next to the extension.
  • To remove: Click the Remove button.

6. Verify

  • Refresh your original tab.
  • Confirm that installHook.js no longer appears in the Network tab.

🧪 Alternative Methods to Disable Extensions

If you want to disable all extensions temporarily:

Option 1: Use Incognito Mode

Most extensions are disabled by default in Incognito.

Option 2: Launch Chrome with --disable-extensions flag

  • Windows: Right-click Chrome shortcut > Properties > add --disable-extensions to the end of the Target field.
  • Mac/Linux: Run in terminal: 
    google-chrome --disable-extensions

âť“ Should You Be Concerned?

In most cases, installHook.js is harmless and helpful. But during performance profiling or debugging:

  • Disable unnecessary extensions
  • Use Incognito mode or launch Chrome with extensions disabled

By managing your extensions, you get more control over your development environment and eliminate unnecessary noise in your tools.

If you found this guide helpful, share it with fellow developers and follow the Mellowtel Team for more practical dev tips!

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