What is chrome-extension:// installHook.js being downloaded in the About Me page?

Question

I recently created several web pages using Three.js. When I check what's being downloaded in Chrome, I see a file called installHook.js. I've searched on SO and other corners of the internet but can't find what it is (maybe it links to React, but I don't use it). Does anyone know what it is and if I can somehow remove it since it is the largest resource being downloaded?

If I click on the link I will see this file

Oddly, I see this on both sites using Web Pack and sites that don't.

Answer 1

The accepted answer is great, but I wanted to add more details in case your browser loads other files from extensions outside of "React Dev Tools" that you don't recognize.

In the network tab (the OP posted a screenshot) you can click on the request to see the details of the request.

Note that this URL specifically uses the chrome-extension protocol, which is our hint that it is a Chrome extension:

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

Please note the identifier in the previous URL: "fmkadmapgofadopljbjfkapdkoienihi". How do you know which Chrome extension the identifier refers to? Copy the identifier to the clipboard. Visit

chrome://extensions/

in Chrome and paste the identifier into the search input at the top of the page. You'll notice that the search results have been filtered to show which extension is loading the file. You can disable the extension by toggling the slider or delete it by clicking the Remove button.

If you click the "Details" button on a specific extension in the

chrome://extensions

window, Chrome should load a specific details page and reiterate that identifier. In this example, Chrome loads the URL:

chrome://extensions/?id=fmkadmapgofadopljbjfkapdkoienihi

...Note that the identifier "fmkadmapgofadopljbjfkapdkoienihi" appears again.

Note other ways to disable extensions, such as

Running Chrome with extensions disabled

with the --disable-extensions or --incognito flag

Answer 2

In my case, installHook.js came from the React Dev Tools Chrome extension. You don't need to worry about this as it won't impact application performance for end users.