Mastodon SSL certificate status
Valid — 85 days until expiry(mastodon.social)
This page shows the Mastodon SSL certificate as served by mastodon.social, read from a live TLS handshake by an independent CertPost probe and rechecked hourly: expiry, issuer, hostname coverage, the full chain, and the negotiated protocol.
Last checked 2026-09-20 07:46 UTC. CertPost is not affiliated with Mastodon.
Certificate details
Hostnames this certificate covers
files.mastodon.social, mastodon.social, www.mastodon.social
Certificate chain as served
Common questions
Is the Mastodon SSL certificate expired?
At the last check, the certificate mastodon.social serves was within its validity period. It expires on 2026-12-14, 85 days from that check.
When does the Mastodon SSL certificate expire?
The certificate mastodon.social is currently serving expires on 2026-12-14 (85 days from the last check). Large services rotate certificates long before that date.
Who issued the Mastodon SSL certificate?
The certificate was issued by YR1.
How is this checked?
A CertPost probe opens a real TLS connection to mastodon.social on port 443 and reads the certificate the server presents, the same way a browser does. The result is cached and refreshed hourly.
Mastodon rotates certificates without downtime. Your own domains are the ones that expire quietly — watch 3 free, no card.
Monitor your certificatesOr run a one-off check with the free SSL checker.