Certbot
EFF's ACME client that gets and renews Let's Encrypt certificates and can configure Apache or NGINX.
- Free plan or free to use
- Open source
- Runs on your own server
About Let's Encrypt
Free, automated certificate authority that issues TLS certificates through the ACME protocol.
Let's Encrypt is a free certificate authority run by the nonprofit Internet Security Research Group. It issues domain-validated TLS certificates through the ACME protocol, so software can request, validate and renew certificates without a person filling in forms. Certificates are short-lived, which makes automatic renewal a requirement: clients such as Certbot, acme.sh and Caddy, and the built-in tools of most control panels, renew on a schedule.
Validation happens over HTTP, TLS or DNS, and DNS validation is needed for wildcard certificates. Hosting providers use it to give every site HTTPS at no cost. Watch the rate limits when issuing many certificates for one domain, and monitor expiry dates yourself so a failed renewal is caught before a site shows a certificate error.
Details
Free plan or free to use
Yes
Not enough info yet on open source, runs on your own server, has an API, built for WordPress sites. Check the tool's own site.
Listing written by HostMomentum, checked 2026-11-03. Report a correction or request removal. Back to ssl and certificates.