TLS / SSL certificate

github.com TLS certificate

github.com port 443 140.82.114.3

VALID

Valid certificate — 39 days remaining.

TLS · 10ms

1s ago

What this means

Browsers will accept this certificate. Plan a renewal before the expiry date below — most CAs auto-renew at 30 days remaining.

Certificate details

Subject CN: github.com
Issuer: Sectigo Limited / Sectigo Public Server Authentication CA DV E36
Valid from: Mar 6, 2026, 12:00 AM (50d ago)
Valid to: Jun 3, 2026, 11:59 PM (1s ago)
Days remaining: 39
Key: EC prime256v1
Signature: ECDSA-PRIME256V1
Hostname match: yes
SHA-256 fingerprint: 97:16:D3:94:41:CA:65:1C:51:BE:78:E9:69:CA:38:5E:C2:13:EC:17:71:5B:8C:91:F0:1E:E6:52:F9:0F:C6:2C

github.comwww.github.com

Full HTTP probe

Run /check/github.com to see live HTTP status, response time, and 24h history alongside this cert.

Renewal reminder

Set a 30-day-before-expiry calendar reminder. Most outages caused by expired certs come from missed renewals.

Check related

Compare with related services or apex/subdomain combinations to spot inconsistencies.

Probe: We open a TLS handshake to port 443 with the supplied hostname as the SNI, read the peer certificate via getPeerCertificate(true), and validate the hostname against subjectAlternativeName via tls.checkServerIdentity.
Counts as DOWN: The TLS handshake fails entirely (TCP refused, handshake timeout, or rejected ClientHello) — we couldn't read a certificate at all.
Counts as DEGRADED: Reserved for soon-to-expire certificates and warning-only validation issues like a self-signed cert. Browsers may still warn even when our check labels the cert valid.
Detail: All certificate details come from getPeerCertificate(true) on the established socket. We do not enumerate cipher suites, test downgrade attacks, or scan for protocol-level weaknesses; this is read-only certificate inspection.
Cadence: Every 5 minutes, in parallel across 4 monitoring regions (US East Virginia, US West Oregon, Europe London, Asia Singapore).
Rate-limited targets: If a host returns 429 or consistently drops connections from our IPs, we cap retries at 3 and report the last observed status — we do not flood the target to confirm the outage.
Data source: Direct probes from our monitoring infrastructure. We do not aggregate crowd reports, Twitter mentions, or DownDetector signals — every result on this page is a live network request.