# Header Override

> Modify HTTP request headers, ModHeader-style (Chrome MV3 / declarativeNetRequest)

Canonical page: [https://chrome-stats.com/d/header-override](https://chrome-stats.com/d/header-override)

## Overview

- **ID:** `header-override`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Massimiliano
- **Category:** web-development
- **Daily users:** 39
- **Weekly downloads:** 6
- **Version:** 0.2.6
- **Last updated:** 2026-05-02
- **First published:** 2026-04-25
- **Size:** 46 KB
- **Data as of:** 2026-09-05
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/header-override/)
- **Privacy policy:** [https://addons.mozilla.org/firefox/addon/header-override/privacy/](https://addons.mozilla.org/firefox/addon/header-override/privacy/)

## Description

Header Override is a developer-focused browser extension that lets you modify outgoing HTTP request headers without leaving the browser. Define profiles of header rules, toggle them on and off, and target specific URLs with glob or regex patterns.

Designed for developers and QA engineers who:
• Test APIs with multiple Bearer tokens for different roles, environments, or users
• Inject custom headers into Swagger UI, OpenAPI explorers, or any browser-based tool
• Bypass simple authentication during local development
• Switch between dev / staging / prod environments without juggling browser profiles

Key features:
• Profiles with independent on/off toggle and color badge
• Per-rule operations: set, append, or remove a header
• URL conditions — glob (<em>://</em>.example.com/*) or regex (/^https:\/\/api./) at profile and rule level
• Multi-preset rules — keep N values for the same header (e.g. SUPERVISOR / OPERATOR tokens) and switch via dropdown
• Per-tab override — lock a profile to a single browser tab
• JWT decoder + editor — click the dot next to an Authorization Bearer token to decode header/payload, see expiry status, edit and re-encode JSON
• ModHeader v2 JSON import/export — full round-trip, with auto-collapse of duplicate-header rules into presets
• Paste cURL — drop a curl command, get a profile with all its headers in one click
• Test URL sandbox — type a URL, see which rules match, optionally fire a real fetch
• Recent matches Activity log
• Light / dark / auto theme (follows OS preference)
• Hotkeys — Ctrl+Shift+H toggles all overrides, Ctrl+Shift+U opens the popup

Privacy: all data is stored locally. The extension does not collect, transmit, or share any user data.

Privacy policy: <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/e86befe29c789b52055422499418ed2ff0678951383fb741989e5369fde1c27d/https%3A//github.com/reservation-extension/privacy-header-override/blob/main/PRIVACY.md" rel="nofollow">https://github.com/reservation-extension/privacy-header-override/blob/main/PRIVACY.md</a>

## Rankings

- #18,197 — Overall
- #6 — override
- #15 — modheader
- #17 — overdrive
- #25 — header
- #139 — modify

## Permissions and access

### Permissions

- `webRequest`
- `webRequestBlocking`
- `storage`

### Host permissions

- `<all_urls>`

## Safety

- **Risk impact:** Moderate risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

## Similar extensions and apps

- [Header Override](https://chrome-stats.com/d/headeroverride) — 7 users
- [HeaderMod](https://chrome-stats.com/d/headermod) — 303 users
- [ModHeader ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-by-modheader-app) — 196 users, 5.00 / 5
- [Overhead — HTTP Header Editor](https://chrome-stats.com/d/overhead-http-header-editor) — 2 users, 5.00 / 5
- [ModHeader V1 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v1) — 5.00 / 5
- [ModHeader V4 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v4) — 1 users, 5.00 / 5
- [ModHeader V2 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v2) — 8 users, 5.00 / 5
- [xHeader - Modify HTTP headers](https://chrome-stats.com/d/xheader) — 2 users
- [ModHeader V5 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v5) — 2 users, 5.00 / 5
- [DevHeaders - HTTP Header Editor & Modifier](https://chrome-stats.com/d/devheaders) — 2 users
- [HeaderMod](https://chrome-stats.com/d/headermod-app) — 17 users
- [ModHeader V3 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v3) — 3 users, 5.00 / 5

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Source: [Chrome-Stats](https://chrome-stats.com/d/header-override)