# OpenModHeader

> Add, rewrite, and remove HTTP request and response headers. Organise rules into profiles and scope them with URL filters.

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

## Overview

- **ID:** `openmodheader`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Multivalence
- **Category:** web-development,privacy-security,tabs
- **Daily users:** 3
- **Weekly downloads:** 3
- **Version:** 1.2.3
- **Last updated:** 2026-08-22
- **First published:** 2026-07-31
- **Size:** 83 KB
- **Data as of:** 2026-09-09
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/openmodheader/)
- **Website:** [https://github.com/Multivalence/OpenModHeader](https://github.com/Multivalence/OpenModHeader)

## Description

Provides the features of the infamous ModHeader extension, but without any malware :D.

<strong>Header editing</strong>
- Set, append, or remove headers on both requests and responses
- Enable or disable any single header without deleting it
- Live count of active headers on the toolbar badge

<strong>Profiles</strong>
- Unlimited independent header sets, each with its own name and colour
- All enabled profiles apply at once, so you can layer an auth-token profile over a feature-flag profile
- Duplicate, rename, recolour, and delete from the profile menu

<strong>URL filtering</strong>
- <code>URL contains</code> — plain substring match
- <code>URL matches regex</code> — full regular expression
- <code>Exclude domains</code> — skip named domains and their subdomains
- <code>Resource types</code> — restrict to <code>xmlhttprequest</code>, <code>main_frame</code>, <code>script</code>, and so on
- Leave filters empty and the profile applies everywhere

<strong>Everything else</strong>
- Global on/off switch, plus <code>Alt+Shift+H</code> from anywhere
- Export and import profiles as JSON to share a setup or check it into a repo
- Open the popup in a full browser tab when you're editing a lot at once
- Follows your system light/dark theme
- Warns you before saving a rule the browser will reject

You may download directly from the source <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/fedde4a25ac975ecd5c37c82f95063ebe63cd70bbc918b6b64f6f7eef4836429/https%3A//github.com/Multivalence/OpenModHeader" rel="nofollow">here</a> if concerned about security.

## Rankings

- #55,047 — Overall
- #11 — modheader
- #174 — header

## Permissions and access

### Permissions

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

### 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 was recently updated in the past month. New updates 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

- [ModHeader](https://chrome-stats.com/d/modheader-firefox) — 19,864 users, 3.37 / 5
- [HeaderMod](https://chrome-stats.com/d/headermod) — 293 users
- [HeaderMod](https://chrome-stats.com/d/headermod-app) — 16 users
- [xHeader - Modify HTTP headers](https://chrome-stats.com/d/xheader) — 2 users
- [ModHeader ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-by-modheader-app) — 246 users, 5.00 / 5
- [ModHeader Pro ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-pro) — 1 users, 5.00 / 5
- [ModHeader V1 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v1) — 5.00 / 5
- [ModHeader By GreatJIN](https://chrome-stats.com/d/modheader-by-greatjin) — 25 users
- [ModHeader V2 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v2) — 8 users, 5.00 / 5
- [ModHeader V5 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v5) — 2 users, 5.00 / 5
- [ModHeader V4 ✨ by modheader.app ✅](https://chrome-stats.com/d/modheader-v4) — 1 users, 5.00 / 5
- [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/openmodheader)