HTTP Debugger is a professional HTTP sniffer and analyzer for developers.
You can use HTTP Debugger to debug HTTP API calls to a back-end and between back-ends.
HTTP Debugger is very easy of use, with clean UI, and short ramp-up time.
It's not a proxy, and does not produce network issues!
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
HTTP Toolkit - Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, Android, CLI tools, scripts and more.
mitmproxy - mitmproxy is an SSL-capable man-in-the-middle proxy for HTTP.
HTTP Headers - HTTP Headers allows you to quickly see the HTTP header information for the current URL.
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.