Introducing InterceptX: The Ultimate Modern Alternative to ModHeader for HTTP Modifications

As web developers, API engineers, and security auditors, we spend a significant portion of our time inspecting and tweaking HTTP traffic. For years, extensions like ModHeader have been the go-to utility for modifying request and response headers on the fly.

However, as the browser extension landscape transitions fully to Manifest V3—bringing stricter security, better performance, and tighter permission rules—many developers are looking for a modern, lightweight, and local-first alternative.

Enter InterceptX.

What is InterceptX?

InterceptX is a high-performance, compact Chrome extension designed to give you complete control over browser network requests. Built from the ground up on Manifest V3 using the declarative declarativeNetRequest API, it is fast, secure, and preserves your battery life by running lightweight matching rules inside the browser engine itself.

Whether you need to bypass CORS policies, simulate mobile user-agents, override security headers, or redirect API endpoints to your local development server, InterceptX does it all with a premium, glassmorphic UI.

Key Features at a Glance

If you are familiar with ModHeader, you will feel right at home with InterceptX—but with several modern upgrades:

1. Request & Response Header Modifications

Inject, append, or strip headers on outgoing requests or incoming responses:

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  Set: Override an existing header or add a new one (e.g., setting custom auth tokens or Origin).


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  Append: Append values to headers like Accept or Cookie.


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  Remove: Completely strip headers (e.g., testing behaviors when header keys are omitted).

2. URL Redirections

Need to test API endpoints or redirect files? InterceptX features a built-in regex redirect engine (using RE2 syntax). You can redirect matching patterns and even use capture groups (e.g., redirecting https://api.production.com/(.*) to http://localhost:3000/\1).

3. Granular URL & Domain Filters

Don't leak modified headers to all websites. InterceptX offers three types of scoping filters:

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  Match: Apply rules only if the request URL matches a wildcard pattern (e.g., *://api.dev.local/*).


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  Exclude: Skip rule execution on static directories or assets (e.g., */static/*).


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  Domain: Tab Domain locks. Restrict modifications to requests initiated from a specific domain hostname only (maps to initiator domain).

4. Resource Type Filters

Filter headers so they only apply to specific resources, such as XHR/Fetch, Main Frame Document, Stylesheet, Script, Image, and more.

5. Multi-Profile Management

Create isolated sets of configurations for different environments (e.g., "Dev Environment", "Staging Debug", "CORS Bypass"). You can switch between profiles, rename, clone, or delete them instantly.

6. Privacy First & Local Storage

Unlike other tools that collect telemetry, InterceptX runs 100% locally. All configurations are saved directly to your browser's local storage. The extension does not collect, log, or transmit any user data.

Getting Started in 3 Simple Steps

Getting up and running with InterceptX takes less than a minute:

1. 
   Install the Extension: Install InterceptX directly from the Chrome Web Store.


2. 
   Add a Rule: Open the extension popup, click + Request Header, and enter X-Custom-Header with a value.


3. 
   Turn It On: Toggle the master Enable switch in the top-right header to Active. The status light will glow green, indicating rules are live.

For complex editing, click the Dashboard button to expand into a gorgeous full-tab dual-column editor.

Why Choose InterceptX over ModHeader?

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  No Bloat: Clean, minimal, developer-focused tool with zero distracting ads.


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  Modern Stack: Built strictly on Manifest V3 keeping performance and security optimal.


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  JSON Profile Portability: Easily back up or share your configurations with team members using the Export and Import buttons.

Conclusion

If you are looking for a reliable, modern, and privacy-conscious header modification utility that doesn't slow down your browser, give InterceptX a try.

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  Install on Chrome Web Store: InterceptX Extension
  


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  Open Source Repository & Bug Tracker: GitHub Repository