Apps with 'API debugging' feature

HTTP Toolkit is a beautiful, cross-platform & open-source HTTP(S) debugging proxy, analyzer & client, with built-in support for modern tools and automatic interception for clients from Docker to Android to iOS.

Modern HTTP client for GNOME with GTK 4 UI, supports GET/POST/PUT/DELETE, custom headers, secure environment variables, projects, request history, cURL export, and syntax highlighting.

HTTP Debugger captures and decrypts HTTP/HTTPS from any Windows app without proxy setup — including HTTP/2, WebSocket, SSE, gRPC and localhost traffic. Edit and replay requests, modify traffic on the fly to test apps without changing server code.

API Traffic Inspector.

Webhook debugging and cron job monitoring in one tool. Inspect, replay, and forward webhooks in real-time. Monitor background jobs with heartbeat, schedule, and event-based checks.

Streamline workflows with our Web API Testing and Monitoring Tool. Automate tests, monitor websites, and ensure seamless API functionality.