# Custom Header Tailor

> Override or add custom HTTP headers on requests and responses. Two lists (request/response), per-rule on/off toggle and optional URL match pattern. Rules are saved locally and persist across restarts. No data collection.

Canonical page: [https://chrome-stats.com/d/mozlla-custom-headers](https://chrome-stats.com/d/mozlla-custom-headers)

## Overview

- **ID:** `mozlla-custom-headers`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Anto
- **Category:** web-development
- **Daily users:** 1
- **Weekly downloads:** 1
- **Version:** 1.0.1
- **Last updated:** 2026-07-04
- **First published:** 2026-07-01
- **Size:** 42 KB
- **Data as of:** 2026-09-05
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/mozlla-custom-headers/)
- **Website:** [https://gitlab.com/mrdjtoto/mozilla-custom-headers.git](https://gitlab.com/mrdjtoto/mozilla-custom-headers.git)

## Description

Custom Headers lets you override or add HTTP headers on the browser's requests and responses.
 Features
  - Two separate sections: Request Headers and Response Headers.
  - Add or remove header rows on the fly (name + value).
  - Enable/disable toggle on every row.
  - Optional per-row "URL match pattern" to limit a rule to specific sites (default: all URLs).
  - Smart behaviour: if a header already exists, its value is replaced; otherwise it is added.
  - Rules are stored locally and persist across browser restarts.
  - Clean, minimal popup, localized in 12 languages.

Privacy
The extension does not collect, store remotely, or transmit any data. Every rule stays in your browser's local storage. Built entirely on the standard declarativeNetRequest API, with no external dependencies.
Open source (MPL-2.0): <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/945fb28a133d823a0d196e8b538669e48f6bfd8822c5690e82385d9c317e3865/https%3A//gitlab.com/mrdjtoto/mozilla-custom-headers" rel="nofollow">https://gitlab.com/mrdjtoto/mozilla-custom-headers</a>

## Rankings

- #130,250 — Overall
- #226 — header
- #245 — override

## Permissions and access

### Permissions

- `declarativeNetRequest`
- `declarativeNetRequestWithHostAccess`
- `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).

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Source: [Chrome-Stats](https://chrome-stats.com/d/mozlla-custom-headers)