Update, August 18, 2025 We have updated the read-only and shutdown dates to ensure that our new Static CT API logs are fully trusted by browsers before switching Oak to read-only in order to avoid any disruption. Let’s Encrypt operates two types of Certificate Transparency (“CT”) logs—some implement the original RFC 6962 API, and some that implement the newer Static CT API. Today we are announcing that on November 30, 2025, we will make our RFC 6962 logs read-only. Past that date, we ...