Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
Fiddler - Fiddler is a debugging program for websites.
tcpdump - tcpdump is a common packet analyzer that runs under the command line.
Proxyman.io - Proxyman is a high-performance macOS app, which enables developers to view HTTP/HTTPS requests from apps and domains.
NetworkMiner - NetworkMiner is a Network Forensic Analysis Tool (NFAT) for Windows.
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.