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lego vs win-acme: catalog facts
lego	win-acme
Best for: Administrators automating TLS certificates from scripts or servers	Best for: Windows server administrators automating Let's Encrypt certificates for IIS and other services
Free Free and open source under the MIT licence.	Free Free and open source under the Apache 2.0 licence.
Windows, Command line	Windows, Command line
Single Go binary that is simple to deploy Works with Let's Encrypt and other ACME authorities All 4 strengths for lego Single Go binary that is simple to deploy Works with Let's Encrypt and other ACME authorities Also usable as a Go library Actively maintained	Simple guided setup for IIS sites Automatic renewal via a scheduled task All 4 strengths for win-acme Simple guided setup for IIS sites Automatic renewal via a scheduled task Many DNS validation plugins and certificate storage options Extensible with PowerShell scripts and C# plugins
Command line only Requires understanding of ACME challenges and DNS or HTTP setup	Windows only Advanced scenarios need familiarity with ACME validation
Downloadable app	Downloadable app
Open source	Open source
License: MIT	License: Apache-2.0
No account needed	No account needed
Needs internet	Needs internet
Official website Full listing and sources Sources for lego go-acme.github.io/lego github.com/go-acme/lego Catalog checked October 2, 2026	Official website Full listing and sources Sources for win-acme win-acme.com Catalog checked October 2, 2026

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