Create profiles that modify HTTP request and response headers. HTTPatch is free, ad-free and built with TypeScript, Preact and Manifest V3 for Chromium browsers and Firefox.
Support development on Ko-fi if you find it useful. Donations do not unlock features.
Options page · Dark view · Header picker
- Edit headers: set, append or remove request and response headers. Search popular header names as you type, or enter your own. Duplicate rules and add notes.
- Organise profiles: name, colour, enable and disable profiles; set toolbar badges and pause every rule with one switch. All enabled profiles can apply at once.
- Scope precisely: filter by request URL and resource type, scope a profile to the current site in one click, or apply it only in a selected browser tab.
- Use focused editors: add request cookies, response Set-Cookie headers and Content-Security-Policy directives without writing the whole value by hand.
- Keep your setup: preview and import JSON profiles, export backups, and sync between devices through your browser account with first-sync merge controls.
- Choose your theme: light by default, with dark and system appearances. No ads, analytics, developer account or paid features.
Browser limits still apply: request-header append supports a fixed allowlist, header values are static, and up to 5,000 active dynamic rules are supported. See the feature comparison for current limits and planned work.
- Open the toolbar popup and create a profile or select one to edit.
- Add a header rule. Choose Request or Response, an operation, a name and a value. The name field filters suggestions as you type.
- Use Scope to this site for the current domain, or open Manage profiles & filters for URL and resource-type filters. Use This tab only when the rule should stay in one browser tab.
Site scope matches request URLs. Requests from the page to third-party domains need their own filters. Selecting a profile changes which one you edit; it does not turn off other enabled profiles. The user guide has examples.
There is no signed public release yet. Build the extension locally with Node.js 22.13 or newer (CI uses Node 24):
npm ci
npm run buildIn Chrome, open chrome://extensions, enable Developer mode, choose
Load unpacked, and select dist/. Use your browser's equivalent extensions
page for other Chromium browsers.
For Firefox:
npm run build:firefoxOpen about:debugging#/runtime/this-firefox, choose Load Temporary Add-on,
and select dist-firefox/manifest.json. Permanent installation requires a
Mozilla-signed package.
Rules and header values are stored locally in plaintext. Browser sync is on by default and includes header values, which may contain credentials. Turn it off in the options page if you do not want those values copied to your browser account; Remove synced copy deletes previously synced data.
HTTPatch has no content scripts, analytics or developer-operated server. It uses the browser's declarative rules API and does not read page content or request bodies. The Ko-fi link opens only when clicked; payments are handled on Ko-fi. See the public privacy policy or PRIVACY.md for details.
npm run lint
npm run format:check
npm test
npm run build
npm run check:manifest
npm run build:firefox
npm run lint:firefox
npm run test:browserRun npm run build before the packaged browser test. See CONTRIBUTING.md
for the full validation, packaging and release process.
HTTPatch is created and maintained by Luke Osland and distributed under the MIT licence. See LICENSE. Both browser packages include the licence and privacy policy.