Portmon Windows 11 |work| Jun 2026

If you only need to see the data coming across the line (rather than the underlying IRPs or driver calls), a simple terminal emulator like Termite or PuTTY is often enough for basic debugging. Com0com & Hub4com

However, the function of Portmon – debugging serial communications – is more alive than ever.

: The tool has not seen a significant update since roughly 2012, leaving it incompatible with modern driver signatures and security requirements. Microsoft Learn Top Alternatives for Windows 11 portmon windows 11

: Supports 64-bit Windows 11 and ARM64. It captures data at the kernel level without needing extra cables.

For professional use on Windows 11, third-party tools have far surpassed what Portmon ever could do. The two market leaders are: If you only need to see the data

Installing Portmon on Windows 11 is a straightforward process:

(Clarification for accuracy – as of the latest Sysinternals updates, Microsoft has integrated serial monitoring capabilities into Process Monitor (Procmon) and offers a separate tool called Portmon that is officially deprecated. The actively maintained tool is actually Sysinternals Serial Port Monitor – a different utility.) Microsoft Learn Top Alternatives for Windows 11 :

Have a specific serial debugging nightmare on Windows 11? Share your story in the comments below (on the original blog publication).

: Offers a "Spy Port" function to monitor low-level traffic and Windows API calls used by other software. It has a free version and a professional version for more advanced diagnostics. Available at serialtool.com .