# HTTP Header Plugin

> Adds custom HTTP headers to requests based on user-defined rules. Automatically add or modify HTTP request headers based on URL matching rules. Supports contains, wildcard, and regex patterns. All rules are stored locally — no data is transmitted.

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

## Overview

- **ID:** `http-header-plugin`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Paul Pepper
- **Category:** web-development
- **Daily users:** 7
- **Weekly downloads:** 3
- **Version:** 1.0.1
- **Last updated:** 2026-02-26
- **First published:** 2026-02-23
- **Size:** 68 KB
- **Data as of:** 2026-09-07
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/http-header-plugin/)
- **Website:** [https://github.com/paulpepper](https://github.com/paulpepper)
- **Privacy policy:** [https://addons.mozilla.org/firefox/addon/http-header-plugin/privacy/](https://addons.mozilla.org/firefox/addon/http-header-plugin/privacy/)

## Description

"Add HTTP Header" lets you define rules that automatically inject or override HTTP request headers on outgoing network requests.

Features:
• Add new headers or override existing ones for matching requests
• Three URL matching modes: Contains (simple substring), Wildcard (* and ?), and Regular Expression
• Rules take effect immediately — no browser restart needed
• Clean options page to add, edit, and delete rules
• Privacy policy displayed directly in the Options UI

How it works:
The extension listens to outgoing requests via the webRequest API. When a request URL matches one of your configured rules, the specified header is added or updated before the request is sent. All rules are stored in your browser's local storage and never transmitted anywhere.

## Rankings

- #39,479 — Overall
- #68 — header
- #82 — plugin
- #189 — override
- #194 — plug

## Permissions and access

### Permissions

- `storage`
- `webRequest`
- `webRequestBlocking`
- `<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).

## Similar extensions and apps

- [Custom Header Tailor](https://chrome-stats.com/d/mozlla-custom-headers) — 2 users
- [HeaderMod](https://chrome-stats.com/d/headermod) — 303 users
- [Modify HTTP Headers](https://chrome-stats.com/d/modify-http-headers) — 51 users, 5.00 / 5
- [HTTP Headers Customize](https://chrome-stats.com/d/http-headers-customize) — 3 users
- [Configurable Header Manager](https://chrome-stats.com/d/configurable-header-manager) — 2 users
- [Header request Injector](https://chrome-stats.com/d/header-request-injector) — 3 users
- [ModHeader By GreatJIN](https://chrome-stats.com/d/modheader-by-greatjin) — 26 users
- [Header Editor](https://chrome-stats.com/d/simple-header-editor) — 6 users
- [Header Ext](https://chrome-stats.com/d/header-ext) — 3 users
- [Header Override](https://chrome-stats.com/d/headeroverride) — 7 users
- [simple-modify-headers](https://chrome-stats.com/d/simple-modify-header) — 6,036 users, 4.62 / 5
- [Headers](https://chrome-stats.com/d/headers) — 520 users, 5.00 / 5

---

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