This article compares various public Certificate Authorities (CAs) that offer free SSL/TLS certificates via the ACME protocol, including Let's Encrypt, Google, ZeroSSL, SSL.com, and Actalis. It details their features such as free SAN limits, wildcard support, certificate lifetimes, and IDN support. The comparison helps users understand the limitations and differences between these CAs when implementing automated certificate management.
Background
ACME (Automatic Certificate Management Environment) is a protocol that automates the process of certificate issuance and renewal, widely used for obtaining SSL/TLS certificates. Let's Encrypt popularized free certificates using this protocol, leading other CAs to adopt similar offerings.
- Source
- Lobsters
- Published
- May 10, 2026 at 02:40 AM
- Score
- 5.0 / 10