Apps similar to PCAPdroid include Wireshark, which is free and open source. Other options are tcpdump, NetworkMiner, Nethogs and CloudShark. You're spoiled for choice with Network Analyzers like PCAPdroid: we list more than 25 alternatives for Windows, Linux, Mac, Android and iPhone.
Mojo Packets™ is web based tool that simplifies trace based analysis and troubleshooting of connectivity/performance issues observed in Wi-Fi (IEEE 802.11) environments.
United States
TUI tool for generating packets of arbitrary input and monitoring packets on any network interfaces (default: eth0). The list of interfaces to be specified is output when packemon --interfaces is run. This tool works on Windows, macOS, and Linux.
Japan
HttpCanary is a powerful HTTP/HTTPS/HTTP2/WebSocket/TCP/UDP packets capture and analyzer app designed for Android platform.
Packetsdump is a free sniffer tool, it is also a general purpose network diagnostic tool for LAN administrators, security professionals, programmers and students who are interested in network traffic transmitted between PC and the whole LAN.
China
justniffer is a TCP sniffer. It reassembles and reorders packets and displays the tcp flow in a customizable way. It can log network traffic in web server log format. It can also log network services performances and extract http content.
PlayCap plays back captures made from Wireshark, tcpdump, WinDump, or any libpcap-based application. PlayCap was originally (and still is) a part of IG Scanner by Signal 11 Software, but was spun off as a separate app and released as Open Source software.
httpry is a tool designed for displaying and logging HTTP traffic. It is not intended to perform analysis itself, but instead to capture, parse and/or log the traffic for later analysis. It can be run in real-time displaying the live traffic on the wire, or as a daemon process...
If you're debugging on a remote machine with a large pcap and no desire to scp it back to your desktop, termshark can help!
packeth is GUI and CLI packet generator tool for ethernet. Primary it is developed and maintained for Linux, but some ports for Windows and MAC have also be done. It allows you to create and send any possible packet or sequence of packets on the ethernet link.
