ModHeader is a powerful browser extension that provides users with complete control over HTTP(S) headers. By allowing you to modify, add, or remove headers in a simple and user-friendly interface, ModHeader is the perfect tool for developers, testers, and web enthusiasts who need to debug and optimize their web browsing experience.

ModHeader can be used for a variety of use cases, such as:

ModHeader is available for most popular web browsers including Chrome, Firefox and Edge, and is free to download and use. Try ModHeader today!



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Why ModHeader

ModHeader is a fast, secured, and light-weight browser extension that allows you to modify HTTP headers with just 1-2 clicks.
ModHeader allow you to set up URL filter, tab filter, window filter, resource type filter, etc.
Consistently rated 4+ stars on Chrome Web Store and used by 800,000+ users.
Easily export and share your profiles with others. Automatically backup your changes to the cloud.
ModHeader is available on Chrome, Firefox, and Edge on Windows, MacOS, and Linux.
ModHeader does not inject ad or sell your data.

ModHeader is featured on

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Modify headers with ease

You can use ModHeader to quickly modify request header, response header, cookie request header, set-cookie response header, etc. With ModHeader, you can pass in custom Authorization header, toggle feature flags, change X-Forwarded-For header, etc., without changing a single line of code.

Toggle changes with a single click

ModHeader allows you to quickly toggle the modification on and off to test different behaviors. You can use ModHeader to toggle feature flags or switch between regions and locales within seconds.

Smart filters

Want to limit your changes to some websites? ModHeader allows you to setup complex URL filter, tab filter, resource type filter, etc. You can avoid leaking your authorization token to other websites unintentionally. With ModHeader's tab filter, you can open two tabs side-by-side to preview your web app with the feature enabled on one tab, and the feature disabled on another tab. Learn more

Modify individual cookies

ModHeader supports modifying individual cookies in the Cookie request header, as well as in Set-Cookie response header. You can use ModHeader to rewrite cookie values, and configure cookie attributes in Set-Cookie response header, without changing a single line of code. Learn more

Configure CSP like a pro

ModHeader helps you generate complex Content-Security-Policy (CSP) response header, test them, and copy them to your production configuration. You can also try out our free CSP editor tool on the web.

Easy collaborations

Want to share your ModHeader profile with your teammate? You can export your ModHeader profile as a URL with the click of a button. The profile URL can be easily imported into ModHeader. You can also configure its visibility to avoid accidental data leakage. Learn more


ModHeader allows you to setup different header modifications and filters on separate profiles, and quickly switch between them. You can create different ModHeader profile for different projects or environments. Learn more

Additional features