Browser Extension

Custom headers.
Dead simple.

Add, manage, and inject custom HTTP headers into every browser request. A lightweight, elegant alternative to ModHeader.

Install Extension About

Features

Everything a developer needs

Unlimited Headers

Add as many custom request headers as you need. Key-value pairs, no limits.

Instant Toggle

Toggle individual headers on/off instantly. Master toggle to enable or disable all headers at once.

Persistent Sessions

Headers persist across browser sessions. Set it once, forget about it until you need to change.

All Request Types

Works on all network requests — XHR, fetch, images, scripts, and more. Complete coverage.

Lightweight & Private

No bloat, no tracking, no unnecessary permissions. Built with Manifest V3 and declarativeNetRequest API.

Clean Dark UI

Modern, clean interface inspired by Apple design. Feels native and stays out of your way.

Use Cases

Built for developers & QA engineers

API Authentication

Add Authorization or API key headers for testing endpoints without modifying code.

Authorization: Bearer eyJhbGci...

Request Debugging

Simulate custom client headers to debug server-side logic and request routing.

X-Debug-Mode: true

Proxy Headers

Inject X-Forwarded-For or other proxy headers for testing load balancers and CDN configurations.

X-Forwarded-For: 192.168.1.1

Content Overrides

Override Accept-Language or Content-Type headers to test internationalization and content negotiation.

Accept-Language: ja-JP

Start using Custom Header.

Install the extension and start adding custom headers in seconds. Free, open, and private.

Install Extension

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Custom headers.Dead simple.