Header Editor Pro – Modify HTTP Headers

Name: Header Editor Pro – Modify HTTP Headers
Author: Charly Brown

Free and open source HTTP header editor. Add, modify or remove request and response headers with unlimited profiles, per-domain filters and one-click pause. No account, no telemetry, no data collection. Available in 7 languages.

Overview

Firefox Add-ons Store

Daily users

Data as of 2026-09-06

Version:

2.6.2

Last updated: 2026-09-04

Features & Capabilities

Header Editor Pro is a free, open source HTTP header editor for developers. Add, modify or remove request and response headers, with no account, no telemetry and no limits.

What it does

Request and response headers — set or append, each one individually toggleable
Unlimited profiles — no three-profile ceiling
Domain filters — scope a profile to the domains you choose, so staging headers never reach production
Pause everything with one click, without losing your configuration
Reorder headers by dragging them
Import and export profiles as JSON
7 languages: English, Español, 日本語, 한국어, Русский, 简体中文, 繁體中文

Typical uses

API testing — send Authorization: Bearer <token> to authenticated endpoints
CORS debugging — add Access-Control-Allow-Origin to reproduce and diagnose
Environment switching — X-Environment: staging against a different backend
Device testing — change User-Agent to compare mobile and desktop responses

Privacy

No data collection, no analytics, no telemetry, no external servers. Your configurations live in local browser storage and never leave your machine. Header rules are applied by the browser itself through the declarativeNetRequest API — the extension does not read page content, and never sees the requests it modifies.

The full source is on GitHub under the MIT licence. Read it, audit it, fork it.

Free, and nobody pays for it

No paywall, no "pro" tier, no nag screens. Nobody funds this work. If you want something improved, open an issue on GitHub and let's talk it through.

Source code: https://github.com/testacode/header-editor-pro-free

User Growth & Download Statistics

Add-on

By:

Charly Brown

Daily users:

Version:

2.6.2 Last updated: 2026-09-04

Version code:

6462348

Creation date:

2025-08-13

Firefox add-on GUID:

header-editor-pro@testacode.com

Firefox add-on numeric ID:

2936157

Weekly download count:

Firefox on Android:

Risk:

Permissions:

Host permissions:

<all_urls>

Size:

69.47KB

Email:

ba*****@gmail.com

URLs:

Website

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-09-06

Compare stats and ranking:

Ranking

# 41,643 ▼ 594

Other rankings

#114 in header keyword 26 ▼ 2#127 in editor keyword 30 ▼ 8#129 in modify keyword 37 ▼ 1#191 in text editor keyword 19 ▼ 3#197 in css editor keyword 27 ▼ 5

For Developers

Monetize with App Pass Boost with Extension Booster

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

Charly Brown

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/header-editor-pro-free/

Email:

ba*****@gmail.com

Website:

https://testacode.github.io/header-editor-pro-free/

Is Header Editor Pro – Modify HTTP Headers Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Header Editor Pro – Modify HTTP Headers requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.

Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Header Editor Pro – Modify HTTP Headers is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.

Risk likelihood analysis details

High This extension was recently updated in the past month. New updates may not be stable or safe.
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