Award-winning free utility to send & receive network packets. TCP, UDP, SSL.
Free Download
Features
Packet Sender can send and receive UDP, TCP, and SSL on the ports of your choosing.
All servers and clients may run simultaneously.
100% Free
Open source 
.
No Ads. No bundles.
Client/Server
Send & Receive.
UDP, TCP, or SSL.
ASCII or HEX
Any data can be defined.
Cross-platform
Windows, Mac, Linux.
Command Line
For automation / scripting
Packet Sender Cloud
Save. Share. Collaborate.
Common Uses
Packet Sender was designed to be very easy to use while still providing enough features for power users.
• Test automation
Using its command line tool or hotkeys
• Testing network APIs
Using the built-in UDP / TCP / SSL clients
• Malware analysis
using the built-in UDP / TCP / SSL servers
• Testing network connectivity/firewalls
by having 2 Packet Senders talk to each other
• Tech support
by sending customers a portable Packet Sender with pre-defined settings and packets
• Security research
Send SSL and then analyze the traffic log.
Screenshots
Windows XP through 10
Mac OS X (x64 Intel)
Linux Desktop (with Qt)
Command Line comes with all versions
More screenshots can be found in the documentation.