Company Overview

Let's Encrypt is the world's largest free SSL/TLS certificate authority, co-founded by Josh Aas and Eric Rescorla in 2014 and operated by the Internet Security Research Group (ISRG). As a non-profit certificate authority (CA), Let's Encrypt provides free SSL/TLS certificates through the fully automated ACME protocol and Certbot client, dramatically accelerating HTTPS adoption across the internet. To date, Let's Encrypt has issued over 3 billion certificates for more than 300 million websites, increasing global HTTPS coverage from under 40% to over 90%.

Related providers: Let's Encrypt Services

Core Products

  • Let's Encrypt SSL Certificates: Completely free SSL/TLS certificates supporting single domain, multi-domain (SAN), and wildcard certificates with 90-day validity and auto-renewal.
  • Certbot (ACME Client): The official ACME client maintained by the Electronic Frontier Foundation (EFF), supporting automatic certificate configuration for Apache, Nginx, and other major web servers.
  • Certbot DNS Plugins: DNS-based domain validation plugins compatible with 50+ DNS providers including Cloudflare, AWS Route53, and Google Cloud DNS.
  • ACME Protocol: Industry-standard automated certificate management protocol (RFC 8555), integrated by hundreds of third-party tools and platforms.

Core Strengths

  • Completely Free, Non-Profit: All certificates are issued and renewed at no cost with no hidden fees, supporting any domain name.
  • Automated Operations: ACME protocol enables fully automated certificate request, renewal, and deployment without manual intervention.
  • Driving HTTPS Adoption: Drastically lowered SSL certificate barriers, raising global HTTPS coverage from under 40% to over 90%.
  • Open Standard: ACME protocol is an IETF standard (RFC 8555), natively supported by AWS, Google Cloud, Cloudflare, and other major platforms.

Key Milestones

  • 2014: Co-founded by Josh Aas and Eric Rescorla, operated by ISRG.
  • 2015: Public beta testing begins; first certificates issued.
  • 2016: General availability launch; mass adoption begins.
  • 2018: Wildcard certificate support introduced.
  • 2020: Cumulative issuance exceeds 1 billion certificates.
  • 2022: Cumulative issuance exceeds 2 billion certificates.
  • 2024: Cumulative issuance exceeds 3 billion certificates.
  • 2026: Continued ACME ecosystem optimization; IPv6 and new validation methods.

Market Position

Let's Encrypt holds a dominant position in the free SSL certificate market, competing with the following providers:

  • ZeroSSL: Primary competitor in free SSL certificates, offering similar ACME services and web management interface.
  • BuyPass SSL: Norwegian free SSL certificate authority offering 180-day free certificates.
  • SSL.com: Paid SSL certificate provider offering OV and EV validation certificates.
  • DigiCert: World's largest paid SSL certificate authority providing enterprise PKI solutions.
  • Sectigo: Global leading commercial CA with a broad SSL certificate product line.