Headerlane: HTTP header editor

Set or remove HTTP request and response headers per URL pattern. No analytics, no tracking, site access asked per pattern.

Headerlane sets, changes or removes the HTTP headers your browser sends, for the sites you choose. Add an Authorization token for your staging API, a feature flag for localhost, or a mobile User-Agent, and switch each one on or off in a click. Moving from ModHeader, which was removed from the Chrome Web Store in July 2026? Import its exported profiles in one step. What it does for free • Request header rules per URL pattern: a host like api.example.com, a path, or a regular expression. Set a header or remove it. • A switch on every rule and every header, and Pause all to turn everything off at once. • The toolbar icon shows how many rules apply on the tab you're on, and its popup lists them so you can switch one off. • Imports a header-editor export file and exports your rules as JSON, so you can copy them to another browser. There's no sync server; the file is the sync. Pro, one payment for up to 3 browsers • Profiles: keep staging, prod debug and local setups apart and switch in one click, or with Alt+Shift+P. • Response headers: change what the server sends back, such as CORS headers for local testing. • Redirects: send a request somewhere else before it leaves the browser, such as production JavaScript to localhost. Every Pro feature is on free for the first 3 days after install, with no card or email. When the trial ends, Pro rules pause; nothing you made is deleted. Private by design • No analytics, no ads, no remote config. • Chrome applies your rules itself. Headerlane never sees your requests or their contents. • Site access is asked for one site at a time, when you add a rule for it. Never "all sites" at install. • Your rules stay in this browser. The only request Headerlane makes is the Pro license check with Lemon Squeezy, who sells it. Clicking Buy opens our site, and Chrome opens a short feedback page there if you uninstall. Honest limits • Works in Chrome 121 and later on a computer. • Chrome lets an extension have up to 1,000 pattern rules, so that's the most Headerlane can apply at once. • It can't return a made-up response body (a mock); Chrome's extension API doesn't allow it. • Chrome doesn't let extensions change requests on chrome:// pages or the Chrome Web Store. Headerlane is made by AISS SOFTWARE and isn't affiliated with or endorsed by Google. Help: hello@aisssoftware.com · https://aisssoftware.com/headerlane