SSLWatchLet's Encrypt certificate expiry: why 90 days (and getting shorter)
Why Let's Encrypt certificates expire quickly, how auto-renewal works and how to monitor it.
Let's Encrypt certificates last 90 days, and the industry is moving to even shorter lifetimes (47 days by 2029). Short lifetimes limit damage from leaked keys and force automation.
Auto-renewal
Tools like certbot, acme.sh, win-acme/simple-acme and Caddy renew at around 60 days. Problems start when renewal silently fails – a DNS change, a firewall, or a moved server.
Monitor it
Check your domains regularly and add a calendar reminder 14 days before expiry as a safety net.