Please do not write regular expressions that begin with (. *), (. *?), (. +), such regular expressions may cause problems with Firefox With this extension, you can modify the request header and response header, cancel a request and redirect a request. It's 100% FREE, no ADs, no data collection. Some links Source Code Helps Report Bugs Help us to translate this extension Migrate to Header Editor If you want to experience the latest version at the first time, you can install our self-distribution version here