# Why is "header name" reduced to lowercase?

RFC 2616 says:

Each header field consists of a name followed by a colon (":") and the field value. Field names are case-insensitive.

So, since 4.0.0, Header Editor will reduce "header name" to lowercase. Except for custom functions: the custom function will still get the original header (except that it has been modified by other rules)

# Can I delete a header in a simple way?

Yes, just modify it to _header_editor_remove_

# Rules disappear

As we know, the rules will disappear or not work

Note: Before doing all of the following, please back up your Chrome/Firefox profile folder!

# Not work in Private Mode

Popup panel and management page is not work in Private Mode of Firefox. But the main features are available

# Chrome

  • Open chrome://extensions/?id=eningockdidmgiojffjmkdblpjocbhgh, enable "Enabled in incognito mode"

# Firefox

  • Open about:debugging, find the Internal UUID of Header Editor (e.g. d52e1cf2-22e5-448d-a882-e68f3211fa76).
  • Open Firefox options.
  • Go to Privacy & Security.
  • Set History mode to "Use custom settings".
  • Click "Exceptions".
  • Paste our URL: moz-extension://{Internal UUID}/ (the {Internal UUID} is the Internal UUID of Header Editor you found in step one), for example, moz-extension://d52e1cf2-22e5-448d-a882-e68f3211fa76/, Then click 'Allow'.
  • Click "Save Changes".

# Rules automatically deleted in Firefox

Thanks to Thorin-Oakenpants and henshin

  • Open about:config, make sure that dom.indexedDB.enabled is true
  • Try to change extensions.webextensions.keepUuidOnUninstall into true, is your problem solved?
  • Open your Firefox profile folder, if there are many files (about a thousand or more) named prefs-xxxx.js files with 0 bytes, closed firefox and deleted them.

# Other questions?

Just submit a issue