Let’s Encrypt uses the ACME protocol to verify that you control a given domain name and to issue you a certificate. To get a Let’s Encrypt certificate, you’ll need to choose a piece of ACME client software to use.
We recommend that most people start with the Certbot client. It can simply get a cert for you or also help you install, depending on what you prefer. It’s easy to use, works on many operating systems, and has great documentation.
If certbot does not meet your needs, or you’d simply like to try something else, there are many more clients to choose from, listed on the main Let’s Encrypt website grouped by the language or environment they run in.
These ACME clients are offered by third parties. Let’s Encrypt does not control or review third party clients and cannot make any guarantees about their safety or reliability.
If you’d like to add a client to the list, please open a pull request on GitHub.