DITM: Developer In The Middle is an extension for Firefox Developer Tools. This allows you to modify the web server's response, like, prettify JS code, add debug print or modify logic, tweak CSS rule etc, in order to investigate the issue on website, without deploying again, or even if it's not your own website. Known issue:

• drop down menu doesn't work if the devtools is opened in separate window, on Firefox 79-90 (see bug 1659618)