Portmon is a legacy utility that monitors serial and parallel port activity on Windows-based systems. Engineers and developers can use it to observe how applications interact with hardware devices that connect through serial and parallel ports.
Does Portmon function properly on current Windows operating systems?
Portmon has not received any updates from Microsoft since the year 2012. The tool is officially supported on 32-bit Windows only. The software fails to function on 64-bit Windows which has become the standard for most modern systems because its 32-bit kernel driver cannot be installed. The GUI displays, but the system fails to begin monitoring operations.
For monitoring COM port communications on contemporary 64-bit Windows systems, Serial Port Monitor serves as a reliable solution which continues to receive updates.
Key Limitations of Portmon
However, it now has several limitations that make it a poor fit for modern development environments.
No updates since 2012, no 64-bit support: Portmon was built for 32-bit Windows environments (Windows 95, 98, NT, XP) and has not been maintained since. It does not run on 64-bit versions of Windows 7, 10, or 11 — which covers virtually all modern installations.
Limited protocol support: Portmon understands standard serial and parallel port IOCTLs but has no built-in support for decoding higher-level protocols such as Modbus RTU or Modbus ASCII, which are widely used in industrial and embedded environments.
No advanced testing capabilities: Portmon does not support replaying communication sessions, simulating serial traffic, or emulating device responses — features found in modern serial monitoring tools.
Serial Port Monitor: Best Portmon Alternative for Windows
Developers, engineers, and system admins can use the software to monitor, record, analyze, and emulate serial port communication between devices and applications. This software is actively maintained and compatible with modern Windows environments, as compared to Portmon.
Key Features of Serial Port Monitor
Serial Port Monitor offers various advanced features, such as:
Real-time monitoring of active serial ports: Serial Port Monitor instantly detects active COM ports and allows you to start monitoring them immediately. Because of this, you can easily identify communication issues between connected devices and software applications.
Track activity across multiple ports at once: Serial Port Monitor supports simultaneous monitoring of multiple serial ports. This makes the software ideal for analyzing complex communication scenarios.
Display captured data in different formats: The software displays the captured data in various formats, including Table, Line, Dump, and Terminal views. This way, it becomes easier to analyze serial communication in the format that works best for your workflow.
Advanced filtering and search features: The software allows you to use dynamic filters to filter relevant traffic and search options to find specific events, errors, or commands in the captured data.
Simulate data transmission over serial ports: Serial Port Monitor’s Terminal mode allows you to simulate data transmission to a device across multiple formats, such as binary, octal, and decimal. It is used to test device behavior and debug communication issues.
Monitor active ports used by other software: Serial Port Monitor captures traffic from ports that are already in use by other applications, which makes it different from other basic tools.
Compatible with various serial protocols and port types: The software is compatible with RS232, RS485, and RS422 communication protocols. It also works with multiple port types, including standard COM ports, virtual COM ports, expansion board ports, and Bluetooth serial ports.
Start Monitoring Your Serial Ports Today
No need to struggle with outdated utilities anymore. You can choose a professional COM port monitoring solution built for modern Windows environments.
You need the following operating systems to monitor your serial ports today using Serial Port Monitor.
Windows Vista: 7, 8, 10, 11 (32-bit and 64-bit)
Windows Server: 2008, 2012, 2016, 2019, 2022
Windows on ARM
This delivers reliable COM port monitoring and debugging for both legacy and modern workstations.
Pricing
The software offers a 14-day free trial option, so you can download the full version of the tool and test every feature for free.
It provides flexible licensing options.
Standard: $59
Pro: $99
Company: $799 (suitable for teams managing up to 10 workstations)
Support
Serial Port Monitor by Electronic Teams remains actively maintained with regular updates and professional technical support.
