Tamper Dev Firefox Jun 2026

Change request headers, POST parameters, and even the server's response body before it reaches the browser.

| Feature | Firefox Tamper (Ext/Native) | External Proxy | | :--- | :--- | :--- | | Ease of setup | ✅ 1-click install | ❌ Requires proxy config | | SSL pinning bypass | ❌ Can be difficult | ✅ Better control | | WebSocket interception | ✅ (with some extensions) | ✅ Full control | | Performance overhead | Low | Medium to high | | Mobile app testing | ❌ No | ✅ Yes | tamper dev firefox

Great for quick security audits without the overhead of enterprise tools. Change request headers, POST parameters, and even the

| Aspect | Firefox | Chrome | | :--- | :--- | :--- | | Built-in request editing | ✅ (Edit and Resend) | ❌ No (requires extension) | | WebSocket frame editing | ✅ Yes (custom frames) | ⚠️ Limited | | Cookie/Storage manipulation | ✅ Excellent UI | ✅ Good | | Extension variety | Fewer dedicated tampering tools | More (e.g., Tamper Dev, Requestly) | | Privacy during testing | Better (no Google telemetry) | Worse | | DevTools performance | Faster for large log payloads | Slower with many requests | For automated tampering (not manual interception)

In Firefox, this is achieved through a combination of its built-in , Storage Inspector , and third-party extensions like Tamper (formerly known as Tamper Dev for Firefox) or Header Editor .

For automated tampering (not manual interception), this extension lets you set rules:

Tamper Dev is the modern evolution of tools like "Tamper Chrome," now optimized for multiple browsers including . Its core functionality revolves around providing granular control over the data flowing between your browser and the server.