Side by side

lego vs win-acme

Both stand on certificate management software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.

lego

Free plan APILinuxMac+1

lego provides certificate operations through both a command-line client and a Go library, with multiple ACME servers and DNS providers. Source installation requires Go 1.25 or later.

Visit lego

Choose win-acme for a free Windows ACME client with scheduled renewal checks and several certificate validation and storage options. Its simple interface targets local IIS, while advanced setups can use its broader configuration and automation features. Community support is through GitHub issues; guaranteed future professional support is connected to sponsorship.

Visit win-acme

The facts

	lego	win-acme
Free plan	Yes	Yes
Open source	Not published	Not published
Runs on	API, Linux, Mac, Self-hosted	Windows
Lowest paid plan	Free or on request	Free or on request
Plans published	1	1
Maker	Not published	Not published
Website	go-acme.github.io	win-acme.com
On certificate management software	#9 of 31	#13 of 31

lego: what it does well

Obtains, renews, and revokes wildcard and SAN certificates
Supports multiple ACME challenge methods
Works with more than 200 DNS providers
Available as a CLI and Go library
Free and open source under MIT

What to know first

Building from source requires Go 1.25 or later
Most listed packages are community maintained

win-acme: what it does well

Creates and installs certificates on a local IIS server.
Schedules daily checks for certificate renewal.
Supports wildcard and international-name certificates.
Offers DNS, HTTP and TLS validation options.
Supports command-line, JSON, PowerShell and C# automation.

What to know first

The current program depends on .NET 7.
Official support is limited to Windows Server 2016 or higher.
Professional support is tied to sponsoring a core developer.

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