osec Monitor cover: certificates now expire in 200 days, soon 47

What changed

• 15 March 2026: maximum certificate lifetime 200 days (was 398).
• 15 March 2027: 100 days.
• 15 March 2029: 47 days.
• Domain validation reuse shrinks on the same schedule, down to 10 days.
• Set by CA/Browser Forum ballot SC081v3 (April 2025).

Why small sites get hurt

• Renewal is now a monthly event, not a yearly one.
• Auto-renew fails quietly: a moved DNS record, a firewall rule, a full disk, an expired API token.
• Nobody notices until a visitor sees a browser warning.
• Domains lapse too: an old card on the registrar account and the whole site disappears.

What osec Monitor checks

• Uptime: your URL every 15 minutes (5 with credits).
• Keyword: alert when the page loads but a phrase is missing ("Add to cart", your brand name).
• Certificate: days left and issuer. Warning 14 days before expiry by default.
• Domain: registration expiry from RDAP. Warning 30 days before by default.
• Down = two failed checks in a row. One email when it goes down, one when it's back.

osec.one console Monitors page with osec.one, Pilotbase and b59.link, each with uptime, SSL days left and domain days left
Console → Monitors: our own sites, with certificate and domain countdowns.

Set it up

1. Sign in at osec.one → Console → Monitors → Add monitor.
2. Enter the URL and, optionally, a keyword that must be on the page.
3. Pick the interval and the warning days.
4. Tick Public status page if you want a link to share.
5. Click Check now to see the first result.

Public status page for osec.one: Operational, uptime bars for each day, last check time
A public status page: one link for your customers, updated every minute.

Good to know

• Free: each check is one request; one monitor every 15 minutes uses 96 of your 500 a day.
• Credits raise the limit and unlock 5-minute checks.
• Checks run from New York. Only public addresses on ports 80 and 443.
• Pair it with osec Scan to grade your HTTPS setup, not just its expiry.

Uptime, certificate and domain expiry alerts. Free for small sites.

Add your first monitor

Sources

• DNSimple, SSL certificate validity changes 2026-2029: https://support.dnsimple.com/articles/announcement-ssl-certificate-validity-changes/
• SSL Insights, 200-day validity from 15 March 2026: https://sslinsights.com/200-day-ssl-certificate-validity/
• CyberInsider, lifespans reduced to 47 days by 2029: https://cyberinsider.com/tls-certificate-lifespans-to-be-gradually-reduced-to-47-days-by-2029/