win-acme

What win-acme is

win-acme is a free, open-source ACMEv2 client for Windows that obtains certificates from Let’s Encrypt and other ACME services. Its simple interface creates and installs certificates on a local IIS server, while an advanced interface supports other setups, including Apache and Exchange. After configuration, win-acme creates a scheduled task that checks daily whether certificates need renewal. It can obtain wildcard and international-name certificates and supports the optional OCSP Must Staple extension. Validation options cover DNS, HTTP and TLS, with examples including acme-dns, Azure, Route53 and Cloudflare. Certificates can be stored in Windows, the IIS Central Store, PEM or PFX files, or KeyVault. Listed compatible providers include Let’s Encrypt, ZeroSSL, DigiCert, Sectigo, Buypass and Keyon. For automation, it supports unattended command-line operation, JSON-file configuration, PowerShell scripts and custom plugins written in C#. Sensitive configuration data is encrypted with Microsoft Data Protection API by default, and cached private keys are encrypted and protected by filesystem access control lists. The current program depends on .NET 7 and officially supports Windows Server 2016 or higher. Community support is available through GitHub issues; guaranteed future professional support is offered in connection with sponsoring a core developer.

Who it suits

win-acme suits Windows users who need certificates for a local IIS server, with additional options for Apache and Exchange. Its validation choices, storage destinations and automation support also suit more advanced certificate setups.

Limits

The current program depends on .NET 7 and officially supports Windows Server 2016 or higher. Older releases may work on older Windows versions, but those versions are unsupported.

Getting started

1. Visit the win-acme website.
2. Use a Windows system; the current program depends on .NET 7 and officially supports Windows Server 2016 or higher.
3. Use the simple interface for local IIS, or the advanced interface for other use cases such as Apache or Exchange.
4. Choose an available ACME provider and validation option.
5. Select a certificate storage destination and configure renewal checks.

Verdict

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.