Overhead — modify HTTP request & response headers and switch whole environments
(LIVE / DEV / Staging) with one click.

• Request & response headers: set, append, or remove.
• Environment groups with mutually-exclusive switching.
• Target by URL wildcard, regex, or a list of URLs — the toolbar badge shows what
actually applies to the current page.
• Edit headers right in the toolbar popup: autocomplete + one-click templates.
• Import your existing ModHeader setup.
• English & German. 100% local, no tracking, no ads, open source.