Header Override
Open-source Chrome, Firefox, and Edge extension to modify HTTP request and response headers…
FreeQAHelpersBrowser Extension5 impressionslaunches Oct 201 comment
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>log in to commentUnlike many header tools that store rules online, Header Override keeps everything in local browser storage and lets you scope rules by URL. I built it to give developers a focused way to add, toggle, and profile request/response headers and cookies for API debugging. It works in Chrome, Edge, and Firefox—let me know what works and what could be better 😊
- Modify request and response headers and cookies
- Scope rules by URL patterns
- Import/export profiles as JSON
- Open‑source, privacy‑first, no tracking
Open-source browser extension to modify HTTP request/response headers and cookies for API debugging.
- for
- Developers, QA engineers, and support staff needing browser-based header manipulation.
- pricing
- open source
- license
- MIT
Key features
- Header editor — Add, edit, and delete request/response headers and cookies in a focused UI.
- URL scoped rules — Apply header or cookie changes only to matching URLs using browser filter patterns.
- Profile management — Create up to five local profiles to switch between projects or test setups.
- Import/Export — Move profiles between browsers via JSON import and export.
- Cross-browser support — Works in Chrome, Edge, and Firefox.
- Local storage only — All rules are stored locally in the extension and never sent to a server.
Use cases
- Send debug headers to staging APIs without code changes
- Reproduce customer-specific headers or cookies for testing
- Toggle backend feature flags while testing UI flows
Header Override FAQ
What is Header Override used for?+
It lets developers, QA teams, and support engineers modify HTTP headers and cookies from the browser for scoped debugging and testing.
Is Header Override an alternative to ModHeader?+
Yes, it is an open-source, lightweight alternative that modifies request/response headers and cookies with local rules.
Are rules sent to a server?+
No, rules are stored locally in the browser extension storage and are not transmitted.
Can rules target specific URLs?+
Yes, rules can be scoped with browser-supported URL filter patterns to affect only matching requests.
Why does Header Override request access to all URLs?+
It needs access to create rules for any site; the extension only sends header values to destinations that match the defined URL filters.
Summarized by DevHunt from headeroverride.com · Oct 17, 2026. Details may change; check the official site.
