Certificate Authority · TRUSTED · United States MON · 14 SEP 2026

Let's Encrypt

Operated by Internet Security Research Group (ISRG) · Since 2015 · Trust status TRUSTED

About

Internet Security Research Group's free, automated certificate authority. The single largest issuer of TLS certificates by volume. Domain-validated (DV) only; no OV or EV. Founded 2015, became publicly trusted 2016. The CA that broke the for-pay certificate model.

CA website Legal repository › Certificate Practice Statement ›