HeaderMod

About

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