# Modify Header Value

> Add, modify or remove a header for any request on desired domains.

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

## Overview

- **ID:** `modify-header-value`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Milen
- **Category:** web-development,privacy-security,appearance
- **Daily users:** 9,880
- **Weekly downloads:** 186
- **Rating:** 3.62 / 5 (66 ratings)
- **Version:** 0.2.1
- **Last updated:** 2026-06-16
- **First published:** 2015-07-06
- **Size:** 110 KB
- **Data as of:** 2026-09-05
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/modify-header-value/)
- **Website:** [https://mybrowseraddon.com/modify-header-value.html](https://mybrowseraddon.com/modify-header-value.html)

## Description

**Modify Header Value** is a versatile Chrome extension that allows you to add, modify, or remove HTTP request headers for any request on specified domains. This makes it an invaluable tool for app developers, website designers, and testers who need to experiment with or debug HTTP headers.

Key features include easy toggling via the toolbar icon, managing multiple header items with options to activate or deactivate them independently, and a detailed tutorial on adding custom headers. It supports complete control over requests to enhance your development and testing workflows. For comprehensive information on HTTP headers, it directs users to Wikipedia's HTTP Header Fields list. Bug reports can be submitted via the extension's homepage, ensuring continuous improvement and support.

## Rankings

- #778 — Overall
- #72 — Web Development
- #112 — Appearance
- #172 — Privacy & Security
- #1 — modify
- #1 — value

## Permissions and access

### Permissions

- `storage`
- `declarativeNetRequest`

### Host permissions

- `<all_urls>`

## Safety

- **Risk impact:** Moderate risk impact
- **Risk likelihood:** Moderate 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).

## Review summary

Summary: Users generally value the core ability to add and tweak HTTP headers in the browser and view it as a useful tool, sometimes as a strong alternative to similar extensions. However, many reviews note reliability problems (headers may not be applied or only affect the first request), a confusing UI, breakage after updates (including MV3 changes), and that it doesn’t affect client-side XHR/fetch requests. Some sites can break when altering headers (e.g., YouTube). Overall, it’s helpful when working, but stability and scope issues limit its consistency.

### Pros

- Core feature: enables adding and adjusting HTTP header values in browser requests.
- Useful for testing and security scenarios; described as very useful by a security researcher.
- Provides a good alternative to similar extensions (e.g., Requestly).
- Gives flexibility to tweak any header you desire.

### Cons

- Unreliable header changes: changes may not apply consistently and often affect only the first request.
- Update-induced breakage: updates can break the add-on or limit its functionality (e.g., MV3 changes).
- UI/UX unclear: enable/disable state isn't clearly indicated.
- Does not affect client-side XHR/fetch requests.
- Can cause site breakages (e.g., YouTube) when modifying certain headers.

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- [AddHeader](https://chrome-stats.com/d/addheader) — 107 users, 4.00 / 5
- [Request Header Modifier](https://chrome-stats.com/d/request-header-modifier) — 41 users, 5.00 / 5
- [Header Tool](https://chrome-stats.com/d/header-tool) — 23 users
- [Custom Header Values](https://chrome-stats.com/d/custom-header-values) — 7 users
- [Netmirror Extension](https://chrome-stats.com/d/netmirror-extension) — 11,502 users, 4.36 / 5

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