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When I run Lighthouse for the project I am working on, I get

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

as no1 causer of unused JS.

How is that making sense from a performance optimization perspective? I can't control what extensions the user runs in his browser. I also can't find anything about the React dev tools in the project.

Would highly appreciate if someone could shed some light on that issue.

lighthouse report sample

Flip
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    can you try disabling react devtools extension in the chrome before running the lighthouse analysis? – neeraj jain Apr 08 '21 at 05:04
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    @neerajjain I tried that and it indeed disappears from the list. still the question remains why this appears at all, since from what I understand it should list things that I, as a developer, can influence. – Flip Apr 08 '21 at 14:50
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    when your pages load this addon will also automatically loaded on the page. this is the simplest explanation. – neeraj jain Apr 09 '21 at 09:23

1 Answers1

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I found the issue is because the file of the devTools is installed when the page is loading... and it is useless in production mode.
So go to the extension and right click on it.
Then go to the manage extensions.
Then find the "Allow this extension to read and change all your data on websites you visit" change it to "on click".

Yunnosch
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abdulrhman Hashim
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