Request Headers | Mod Header Free alternative

About

NOTE: Soon Request Headers will be open-sourced!

Request Headers lets you add custom HTTP request headers to the sites you browse — and turn them on or off with a single click, without deleting anything.

Perfect for developers and QA: test APIs behind auth headers, switch environments, debug feature flags, or send any custom header your workflow needs.

FEATURES

• Create headers with a name and value — toggle each one on/off individually
• URL filtering — apply a header to all sites or restrict it to a pattern like *://api.example.com/*
• Master switch — disable everything at once without losing your setup
• Profiles — keep separate header sets (e.g. Dev, Staging, Production) and switch between them instantly
• Export / Import — back up your configuration as JSON and restore it anywhere
• Clean, compact popup UI — no clutter, no ads

PRIVATE BY DESIGN

This extension is built on Manifest V3's declarativeNetRequest API. That means it only declares rules ("add header X with value Y") and the browser itself applies them at the network layer. The extension cannot read the content of your requests or responses — by design, not by promise.

• No data collection
• No external servers — everything stays in your browser's local storage
• No analytics, no tracking
• No runtime dependencies

NOTES

Some browser-controlled headers (such as Host, Content-Length, and certain Sec-* headers) cannot be modified by any extension for security reasons.

Works on Chrome, Edge, Brave, and other Chromium-based browsers.