Acme CA Comparison
15 hours ago
- #Certificate Authorities
- #ACME
- #SSL/TLS
- This page compares public certificate authorities (CAs) offering free certificates via ACME, detailing their implementations and limitations.
- Key comparison metrics include free SAN limits, wildcard support, certificate lifetime, IDN support, chain info, rate limits, and notes on specific CAs.
- Let's Encrypt offers up to 100 names, 90-day lifetime, with staging environment and quick start guides.
- ZeroSSL allows 100+ names, customizable lifetime from 1 to 90 days, and uses a custom REST API alongside ACME.
- SSL.com provides 100+ names and 90-day lifetime, but caution is needed as funds in account may lead to charges for paid certificates.
- Actalis limits to 1 name + www, 90-day lifetime, with support for IP certs only on paid OV plans and issues with challenge retries.
- ACME protocol feature support varies: External Account Binding is required by most except Let's Encrypt, multi-perspective validation and SXG support are notable security features.
- Specific notes include Google's 90-day default lifetime, BuyPass removal after October 15, 2025, and challenges with account endpoints for some CAs.