Header Modifier

About

Take control of HTTP headers on a per-domain basis. Add, remove, or rewrite
request and response headers, block unwanted requests, and redirect traffic,
all organized into switchable profiles. Everything else stays untouched.

Set up a profile for your dev environment with auth tokens and CORS headers.
Set up another for debugging with custom trace IDs. Switch between them
from the popup without touching your rules.

- 🔧 Modify request and response headers: set, append, or remove
- 🎯 Target by domain, subdomains, URL pattern, or regex
- 🚫 Block matching requests before they leave your browser
- 🔀 Redirect matching requests to a different URL
- 👤 Switch between profiles (Dev, Staging, Debug CORS) with one click
- 🔄 Drop in dynamic placeholders: `{{uuid}}`, `{{timestamp}}`, `{{random_int}}` and 13 more
- 🔍 Filter rules by HTTP method: GET, POST, PUT, DELETE, and others
- 📤 Export and import profiles and rules as JSON
- ↕️ Drag and drop to reorder rules
- 📋 Duplicate rules and detect when they shadow each other
- ⏹️ Toggle the whole extension off without losing your rules
- 🌍 Available in English, Spanish, Chinese, Hindi, and Russian
- 🚫 No ads, no tracking, completely free and open source