HeaderMod

Modify HTTP request and response headers. Create profiles, filter by URL, and toggle headers on the fly.

FEATURES • Request headers — set, append, or remove headers on outgoing requests (e.g. Authorization, X-Forwarded-For, custom X-* headers). • Response headers — set, append, or remove headers on responses (e.g. Access-Control-Allow-Origin for CORS testing). • Cookies — append name=value pairs to the outgoing Cookie header without touching the browser's stored cookies. • Redirects — map matching URLs to another URL, e.g. point a production script at http://localhost:3000. Wildcard patterns or regexes with backreferences in the target. • Query parameters — add/replace or remove query params on matching URLs (e.g. force ?debug=1 everywhere). • URL filters — include filters restrict modifications to matching URLs (* wildcards, e.g. *://api.example.com/*); exclude filters carve out URLs that must never be touched. • Tab scoping — optionally pin a profile to specific tabs so the rest of your browsing is untouched. • Value placeholders — {{timestamp}}, {{isodate}}, {{uuid}}, {{random}} in header, cookie, and param values and redirect targets. • Profiles — create, rename, and switch between independent rule sets. • Per-rule toggles and a global pause button. • Badge counter showing how many modifications are currently active. • Export / import profiles as JSON. PRIVACY No data collection, no analytics, no remote servers. Your rules are applied natively by the browser (declarativeNetRequest) — the extension never reads your traffic. Fully open source: https://github.com/danube20/headermod