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.

This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit. (http://www.openssl.org/)

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.