A nonprofit Certificate Authority providing TLS certificates to 550 million websites. Read all about our nonprofit work this year in our 2024 Annual Report.

Let’s Encrypt issues certificates through an automated API based on the ACME protocol. In order to interact with the Let’s Encrypt API and get a certificate, a piece of software called an “ACME client” is required.

Let's Encrypt is a free, automated, and open Certificate Authority brought to you by the nonprofit Internet Security Research Group (ISRG). Read all about our nonprofit work this year in our 2024 Annual Report.

Announcing Six Day and IP Address Certificate Options in 2025 In addition to our standard certificates, Let’s Encrypt will introduce new short-lived certificates to improve security and agility for the Web PKI.

Let’s Encrypt is a free, automated, and open Certificate Authority (CA), run for the public’s benefit. It is a service provided by the Internet Security Research Group (ISRG). We give people the digital certificates they need in order to enable HTTPS (SSL/TLS) for websites, for free, in the most user-friendly way we can.

5 天之前 · Announcing Six Day and IP Address Certificate Options in 2025 In addition to our standard certificates, Let’s Encrypt will introduce new short-lived certificates to improve security and agility for the Web PKI.

2024年6月26日 · We let people and organizations around the world obtain, renew, and manage SSL/TLS certificates. Our certificates can be used by websites to enable secure HTTPS connections. Let’s Encrypt offers Domain Validation (DV) certificates.

2024年6月26日 · The objective of Let’s Encrypt and the ACME protocol is to make it possible to set up an HTTPS server and have it automatically obtain a browser-trusted certificate, without any human intervention. This is accomplished by running …

2023年12月27日 · The error says: cause: Error [ERR_TLS_CERT_ALTNAME_INVALID]: Hostname/IP does not match certificate's altnames: IP: 98.25.54.173 is not in the cert's list: Are you trying to connect to the website by IP address by any chance?

2024年8月2日 · (TLS) Tells curl to use the specified certificate directory to verify the peer. Multiple paths can be provided by separating them with ":" (e.g. "path1:path2:path3"). The certificates must be in PEM format, and if curl is built against OpenSSL, the directory must have been > processed using the c_rehash utility supplied with OpenSSL.