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acme.sh vs lego: catalog facts
acme.sh	lego
Best for: Administrators automating certificate issuance and renewal	Best for: Administrators automating TLS certificates from scripts or servers
Free Free and open source under the GPL-3.0 license.	Free Free and open source under the MIT licence.
Command line	Windows, Command line
Issues and renews certificates through ACME Supports wildcard and ECDSA certificates All 3 strengths for acme.sh Issues and renews certificates through ACME Supports wildcard and ECDSA certificates Runs with Bash, dash, or sh	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
Requires a Unix shell environment. Certificate issuance and renewal require access to an ACME service.	Command line only Requires understanding of ACME challenges and DNS or HTTP setup
Downloadable app	Downloadable app
Open source	Open source
License: GPL-3.0-only	License: MIT
Not stated if an account is needed	No account needed
Not stated if it works offline	Needs internet
Official website Full listing and sources Sources for acme.sh github.com/acmesh-official/acme.sh Catalog checked October 8, 2026	Official website Full listing and sources Sources for lego go-acme.github.io/lego github.com/go-acme/lego Catalog checked October 2, 2026

“Not stated” means we have not confirmed it. Features can vary by device and plan.