There any free Serial port sniffer for monitoring COM port communication?

Question

Is there any completely free serial port sniffer software available? I'm specifically looking for a tool similar to Electronic Team "COM Port Monitoring" or "Free Serial Analyzer."

To clarify, I’m not asking about basic serial monitors like TeraTerm or Docklight that allow you to open a COM port and send/receive data from a device.

I'm looking for software that can passively monitor and log the data exchanged between a program like TeraTerm and a serial port, providing real-time insights into the communication without directly interacting with the devices involved.

Answer 1

Hi Kerry,

Thanks for your post. Based on my research, Microsoft didn’t provide any full free Serial port sniffer for monitoring COM port communication. You can see if some 3-third party software can meet your requirements.

For example,

Serial Port Monitor | FREE Serial Port Monitor [for Windows] (com-port-monitoring.com)

Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it. Hope this helps.

Best Regards,

Ian Xue

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Answer 2

Hello Kerry Bills

You could use PuTTY (https://www.chiark.greenend.org.uk/~sgtatham/putty/ ) to monitor serial port communication or try SerialMon (https://www.serialmon.com/).

Kind regards
Dominique