Development Windows
Serial Port Monitor
Capture and inspect Windows COM-port traffic with Serial Port Monitor. Log serial exchanges, compare sessions and analyze Modbus data; a 14-day trial is available.
- Operating system
- Windows Vista, 7, 8, 10 and 11; Windows Server 2008, 2012, 2016, 2019, 2022 and 2025
- Architecture
- Publisher lists 32-bit, 64-bit and Windows on ARM support
- Download package
- EXE installer
System support is publisher-reported, not locally tested. The selected EXE's internal architecture was not inspected. Release notes say Windows XP and Server 2003 support ended in build 9.5.589.
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What is Serial Port Monitor?
Serial Port Monitor records data passing through Windows serial ports so developers and hardware technicians can inspect communication between an application and a connected device. It works with RS232, RS422 and RS485 communication and supports physical ports, virtual COM ports and USB-to-serial adapters. Multiple ports can share one monitoring session, making related exchanges easier to review together.
Captured traffic can be examined in table, line, dump, terminal and Modbus views. Save a session to reopen later, redirect captured data to a file, or use session comparison to locate differences between captures. The publisher also documents Modbus RTU and ASCII decoding and playback of captured data to a serial interface.
Check the edition before choosing it for an existing application: monitoring a port already opened by another program and the advanced Send dialog are listed as Professional/Company features. This is commercial software with a fully functional 14-day trial, not a permanently free utility. The gallery image is a historical Serial Port Monitor 5.0 interface from Softonic, not a screenshot of the current build.
What it offers
- Monitor several COM ports in one session, including physical ports, virtual ports and USB-to-serial adapters.
- Inspect captured traffic through table, line, dump, terminal and Modbus views.
- Save and reopen monitoring sessions, record data to files and compare sessions.
- Decode Modbus RTU and Modbus ASCII communication.
- Replay captured data to a serial port; advanced sending controls depend on the edition.
Good to know
- The fully functional trial lasts 14 days; continued use requires a paid license.
- Monitoring a port already opened by another application and the advanced Send dialog require Professional or Company edition.
- Publisher release notes list build 9.5.602, while the product overview still says 9.5.600. The HEAD check verifies the linked EXE endpoint, not the build inside that file.
Product images
Sources
References used for this listing. Retrieval dates do not indicate hands-on testing.
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