Radardue2027 readiness
Certificates are getting shorter. Radardue looks at how each host renews today and flags the ones whose habits will break when they do.
What's changing
| Date | Change |
|---|---|
| 15 Mar 2026 | Public certificates limited to 200 days. |
| 10 Feb 2027 | Let's Encrypt's default certificate lifetime drops to 64 days. |
| 15 Mar 2027 | Public certificates limited to 100 days. |
| 15 Mar 2029 | Public certificates limited to 47 days. |
The full timeline and a checklist are in our guide to 47-day certificates.
What Radardue checks
For each certificate, Radardue looks at when the host's previous certificates were issued (from its own daily checks and public Certificate Transparency logs) and works out the usual gap between renewals. The result appears on the item page and in client reports:
| Flag | Meaning |
|---|---|
| At risk | A Let's Encrypt host that renews on a fixed cycle of roughly 50 to 70 days. Once certificates last 64 days, a 60-day job leaves almost no margin, and one missed run means an outage. |
| Worth watching | A certificate valid for more than 100 days. That's usually renewed by hand, and will need renewing about four times as often from March 2027. |
| Looks fine | The host renews often enough, or the certificate is already within the 2027 limits. |
| Not enough history | Fewer than three renewals seen so far. Radardue keeps learning from its daily checks. |
Clearing an "at risk" flag
- Renew by time remaining, not on a fixed interval. Configure the ACME client (certbot, acme.sh, Caddy, Traefik, cert-manager and so on) to renew when about a third of the lifetime is left, instead of every 60 days.
- Use ARI if you can. ACME Renewal Information lets the certificate authority tell your client when to renew. Recent versions of many clients support it.
- Remove hard-coded schedules. Look for cron jobs and scheduled tasks that renew on a fixed day count.
The flag updates on its own as Radardue sees the host renew on the new schedule.
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