Best HTTP Header Spy Alternatives ranked by AI · updated Aug 2026

💡 Pick it when you need to modify headers, not just inspect them, while staying inside the browser.

ModHeader is a browser extension and web tool for viewing and modifying HTTP request and response headers. It is aimed at web...

💡 Choose it when header inspection is part of a larger workflow involving redirects, response overrides, or team testing.

Requestly is a powerful tool to modify network requests. It can be used for URL redirection, header modification, modifying response data, etc.

💡 Pick it when you need to inspect and edit traffic beyond a single browser page, including mobile and API clients.

HTTP Toolkit is a suite of tools designed for debugging, testing, and building with HTTP(S). It provides powerful features for monitoring and...

💡 Choose it for free, scriptable traffic interception across browsers, APIs, devices, and development environments.

mitmproxy is a free and open-source interactive HTTPS proxy.

💡 Use it when you need a mature desktop proxy for capture, replay, and troubleshooting across multiple clients.

Fiddler is a free web debugging proxy for any browser, system, or platform.

💡 Pick it for a polished native proxy, especially when debugging iOS or Android app network traffic.

Proxyman is a native HTTP debugging proxy for inspecting web, desktop, and mobile application traffic. It provides certificate management, request editing, breakpoints,...