Header Editor icon

Header Editor

An open-source extension that rewrites headers, redirects and blocks requests with rules you set.

Reviewed by Xplorekit's independent developer · Last checked · How we choose

Add to Chrome Open source · Chrome Web Store · Source

Why it's a strong pick

Header Editor does a focused job: rules for requests and responses, with no code to write. It is open source under GPL-2.0-or-later, and its code is public on GitHub. It uses Manifest V3, Chrome's current extension format. The project made its latest release on 24 September 2026. The Chrome Web Store build is the Lite version, which has no custom functions.

What it does

You write rules, and Header Editor applies them to the pages you load. The README says it can modify the request, including request headers, response headers and the response body, redirect requests, and cancel requests. The Chrome Web Store build is the Lite MV3 version. It uses Chrome's declarativeNetRequest system, so custom functions and some full-version features are not in it. The full version is a separate manual install.

Key features

  • Header rules. Change request headers and response headers.
  • Redirects. Send a request to another URL.
  • Request blocking. Cancel requests you do not want.
  • URL filter. Added in release 5.3.0, per the release feed.
  • Backups. Back up to OneDrive, Google Drive or WebDAV (5.4.0), plus Yandex and S3 (5.4.1).
  • Lite build. The store version has no custom functions.

Who it's for

Header Editor is for developers, testers and tinkerers who need to change headers, redirect or block requests without writing code. If you need custom functions, the Chrome Web Store build will not give you those, because it is the Lite version.

What permissions does Header Editor ask for?

The project's build files list tabs, storage, unlimitedStorage, declarativeNetRequest and debugger. They also list access to all sites, including websocket and file URLs. That is broad, because the tool must touch requests on any page. We read the source, not the store build, so check the install prompt.

Does Header Editor collect my data?

The README says "100% FREE, no ADs, no data collection." That is the developer's own claim, not an audit by us. We could not read the developer's privacy policy when we checked, so read it before installing. The extension also asks for the debugger permission and access to all sites, so review the install prompt as well.

Why is the Chrome version called Lite?

Chrome's Manifest V3 rules limit what an extension can do with requests. The Chrome Web Store build uses declarativeNetRequest, and the project turns off custom functions there. The README links a separate full version that you install by hand. We did not review the exact differences.

Can it change the response body?

The README lists the response body among the things Header Editor can modify, and it says the debugger permission is for modifying the response body in Chrome. We did not test this in the Lite build, so check it on your own pages.

FAQ

Is it open source? Yes, under GPL-2.0-or-later.

Does it use Manifest V3? Yes. The Chrome build is MV3.

Can I use custom functions in the store version? No. The store build is the Lite version without them.

Good to know

Test a new rule on one page first. A bad header or redirect rule can break a site, and you can turn the rule off in the extension. Keep your rules short and give each one a clear name.

Other developer tools to compare

Header Editor is one of 13 picks in our developer tools guide:

  • Redux DevTools: Inspect actions and state in Redux apps, with time-travel debugging and action replay. Open source.
  • Apollo Client Devtools: Inspect queries, mutations and the cache in Apollo Client apps, and run queries in the Explorer. Open source.
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  • Lighthouse: Run performance and quality audits on the current page from a popup. Open source.
  • JSON Formatter: Turn raw JSON pages into a readable tree. Open source.
  • React Developer Tools: Inspect React components, props and state in a Chrome DevTools panel. Open source, by Meta.
  • Vue.js devtools: Debug Vue 3 apps in a DevTools panel. Vue 2 apps need the older v6 extension. Open source.
  • Requestly: Open-source HTTP interceptor: redirect URLs, modify headers and mock requests while you test.
  • Solid DevTools: Inspect SolidJS component state and the reactivity graph in a DevTools panel. Needs the solid-devtools package in your app. Open source.
  • Ember Inspector: Adds an Ember tab to DevTools to inspect objects in Ember.js apps. From the Ember.js project. Open source.
  • MobX Developer Tools: Track observable changes and inspect the dependency tree in MobX apps. Open source.
  • Refined GitHub: Simplifies GitHub and adds 100+ small improvements for repos and pull requests. Works on GitHub.com only. Open source.

This is a third-party extension, not built or maintained by Xplorekit. We link to the official Chrome Web Store listing — install and permissions are entirely between you and the extension's own publisher.