Headerwise

Change HTTP request and response headers in Chrome and Edge. Set, append or remove headers per profile, limit a profile to some URLs or keep it off others, and import your old ModHeader profiles.

It runs entirely in your browser. No account, no analytics, no network requests of its own. Rules are applied by Chrome itself through declarativeNetRequest, so the extension never reads the pages you visit.

You don't have to take "no network requests" on trust: the manifest sets connect-src 'none' for every extension page and the background worker, so the browser itself blocks any request Headerwise might try to make. npm run test:live checks this (fetch, image, beacon, worker) in a real browser.

Site: https://protemir.github.io/headerwise/ · Privacy: https://protemir.github.io/headerwise/privacy.html

ModHeader turned off and its Export button gone? How to get your profiles back.

Setting headers in Selenium, Playwright or Puppeteer tests (where chrome-modheader used to go)? There is an automation build with a fixed id and a URL to set headers from your test.

Status

Free, and staying free. Install it from the Chrome Web Store (Edge, Brave and Vivaldi install it from there too). The newest build is also in the latest release: unzip it and "Load unpacked" in chrome://extensions with Developer mode on, or build it yourself (below). Bugs and requests: GitHub Issues.

Develop

npm ci            # exact versions from package-lock.json
npm test          # unit tests, plain node --test
npm run build     # builds the extension into dist/
npm run build:automation # dist-automation/: fixed id, site access, automation.html
npm run test:live # loads dist/ into a throwaway Chrome profile and checks real requests
                  # (add -- --browser edge for Edge; also checks dist-automation/ if built)

Then open chrome://extensions, turn on Developer mode, click "Load unpacked" and pick the dist folder. Click the Headerwise icon and allow access to sites.

How rules map to Chrome

Each enabled profile becomes one modifyHeaders rule per "only on" filter (or one rule for all URLs if there are none). "Never on" filters with a plain domain become excludedRequestDomains. The first profile in the list has the highest priority.

Chrome has no way to say "skip URLs matching this regex", so a regex (or any other non-domain) "never on" filter becomes an allow rule with the profile's priority. Chrome then ignores all header rules with that priority or lower on matching URLs. To keep this from switching off other profiles, profiles with such filters are placed below the rest, and Headerwise warns if that changes which profile wins a header. Chrome only allows append for a short list of request headers; Headerwise tells you when it skips one.

License

MIT, see LICENSE.