NSSM
nssm.cc
What it is
NSSM is a Windows service helper that runs an application as a service, watches its process, and responds when it exits. A graphical interface installs or removes services, while command-line options support scripted configuration. On exit, NSSM can restart the application, ignore the event, terminate itself, or exit uncleanly so Windows recovery actions can run. It records its own progress in the Windows system Event Log and can redirect the monitored program’s input and output. Output files can rotate at a configurable size, including while the program continues running. Administrators can set process priority and CPU affinity, and start, stop, or query services. NSSM provides 32-bit and 64-bit binaries and says it should work on Windows 2000 or later. It is public domain, with source usable for any purpose. The site lists version 2.24 from 2014-08-31 as latest, plus a 2017 prerelease. Administrator access is required; documented bugs affect newer startup, XP, and large log rotation.
Spec sheet
- Purpose
- NSSM runs an application as a Windows service, monitors it, and can restart it if it exits.Read 4 Oct 2026 · nssm.cc
- Support
- The site directs users to the Windows Application Event Log for troubleshooting and to the author's email address in repository commits to report bugs.Read 4 Oct 2026 · nssm.cc
- License
- NSSM is public domain and may be used with its source code for any purpose.Read 4 Oct 2026 · nssm.cc
- Maker
- The NSSM site identifies Iain Patterson as its author.Read 4 Oct 2026 · nssm.cc
- Build and distribution
- The site says NSSM is built with Jenkins and that its Chocolatey package is maintained by a third party and may not match the latest site build.Read 4 Oct 2026 · nssm.cc
- Exit behavior
- When an application exits, NSSM can restart it, ignore the exit, exit itself, or exit uncleanly to trigger service recovery actions.Read 4 Oct 2026 · nssm.cc
- Known issues
- The bugs page lists version 2.24 issues affecting newer Windows service startup, Windows XP crashes, log rotation over 4 GB, and other cases.Read 4 Oct 2026 · nssm.cc
- Logging and I/O
- NSSM logs its progress to the Windows system Event Log and can redirect the monitored application's input and output.Read 4 Oct 2026 · nssm.cc
- Other controls
- NSSM can set an application's priority class and CPU affinity, and can start, stop, and query services.Read 4 Oct 2026 · nssm.cc
- Output rotation
- NSSM can rotate output files when they reach a configurable size, including while the application is running.Read 4 Oct 2026 · nssm.cc
- Release status
- The page lists version 2.24, dated 2014-08-31, as the latest release and a 2.24 prerelease build dated 2017-04-26.Read 4 Oct 2026 · nssm.cc
- Security and privileges
- NSSM requires administrator access to manage services, and the site warns that bugs can cause severe system issues.Read 4 Oct 2026 · nssm.cc
- Service setup
- It provides a graphical interface for installing and removing services, and its command-line options can configure services from scripts.Read 4 Oct 2026 · nssm.cc
- Windows support
- The download page says NSSM should work on Windows 2000 or later and includes 32-bit and 64-bit binaries.Read 4 Oct 2026 · nssm.cc
Plans and prices
Strong points and limits
Strong points
- Free public-domain software
- Graphical and command-line service setup
- Restart and recovery behavior options
- Output redirection and size-based rotation
- 32-bit and 64-bit Windows binaries
Limits
- Requires administrator access
- Documented bugs affect newer Windows startup
- Latest listed release dates from 2014
- Windows-only platform
Who it suits
NSSM suits Windows administrators who need to run existing programs as services and control restart behavior. It also fits scripted service setup and users needing redirected output or Event Log progress.
Verdict
NSSM provides detailed service management for Windows programs, including restart policies, logging, I/O redirection, and process controls. Its age, administrator requirement, and documented compatibility issues deserve attention before deployment.
Where Specifiction places it
- Startup Manager Software#12 of 307.6