Packet Sender has built-in servers for UDP and TCP to receive unsolicited packets on the ports of your choosing. Beyond just normal UDP and TCP, Packet Sender's fully multi-threaded client supports any number of persistent TCP and SSL (TLS) connections.

100% Free

Open source .
No Ads. No bundles.


Send UDP, TCP, or SSL.
Receive UDP or TCP.


Any data can be defined.


Windows, Mac, Linux.

Command Line

For automation / scripting

Persistent TCP and SSL

Stay connected while sending your (encrypted) data.

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 TCP, UDP, SSL clients

• Malware analysis

using the built-in UDP and TCP 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.


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.