Header Editor от 泷涯, 道滿

With this extension, you can modify the request header, response header, and response body, cancel a request, redirect a request.
It's 100% FREE, no ADs, no data collection.

You can aslo try Lite version

Mozilla usually takes more than a week to review new versions. If you want to experience the latest version at the first time, you can install our self-distribution version

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Migrate to Header Editor