Let's Encrypt

Our 2025 Annual Report highlights the progress we've made toward a better Internet.
Let's Encrypt is a Certificate Authority that provides free TLS certificates, making it easy for websites to enable HTTPS encryption and create a more secure Internet for everyone. Let's Encrypt is a project of the nonprofit Internet Security Research Group.
Start securing your websites with free SSL/TLS certificates from Let's Encrypt. In order to get a certificate for your website's domain, you have to demonstrate control over the domain.
Learn about our certificate issuance process and best practices.
Choose from our recommended ACME clients to automatically manage your certificates.
Join our community forum for technical assistance and knowledge sharing with experts, volunteers, and ISRG staff.
Your donation helps keep Let's Encrypt free and accessible to millions of websites around the world. Join us in securing the Internet, one site at a time. Every contribution makes a difference, whether you're an individual or a company.
Companies who rely on or value our work to encrypt the Web can financially support Let's Encrypt. Join companies big and small to make this work possible!
Did you know Let's Encrypt has two sibling projects? Let's Encrypt and these two projects are operated by Internet Security Research Group (ISRG), a 501(c)(3) public benefit organization focused on making the Internet more secure and privacy-respecting.
Focused on memory safety in critical Internet infrastructure through the use of memory safe programming languages.
A privacy-respecting system for collecting and aggregating metrics, built on Multi-Party Computation.
A Let’s Encrypt egy ingyenes, automatizált és nyílt hitelesítésszolgáltató (Certificate Authority), amelyet a nonprofit Internet Security Research Group (ISRG) működtet. Tudj meg többet idei nonprofit tevékenységünkről a 2025-ös éves jelentésünkben.