By Sarah Gran · October 7, 2026 On February 10, 2027, all Let’s Encrypt subscribers will move to certificates with 64 day lifetimes by default unless they select an even shorter lifetime (45 or 6 days, as previously announced). This means that any certificate we issue or renew on and after that date will have a 64 day validity period, and we expect the last 90-day certificate to expire on May 11, 2027. We will not revoke valid certificates as a part of this process. We will switch to issuing 64 ...