SSL/TLS Certificate Lookup

Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted

SSL/TLS Certificate for heroku.com

Valid
Issued by (CA)
Let's Encrypt
Subject
heroku.com
Valid from
Sep 7, 2026
Valid until
Dec 6, 2026 (65 days remaining)
Public key
EC 256-bit
Serial
052939EA6145C2AA74C4BCFEFA480A28175F
SHA-256 fingerprint
6F:85:37:BF:3D:A4:62:5E:F6:53:5F:87:3F:92:2D:16:D5:3F:8A:45:5A:2F:54:AB:BF:B5:9F:9F:17:C9:0C:4B
Chain
YE1 → Root YE → ISRG Root X2 → ISRG Root X1
Subject Alternative Names (2)
heroku.com, www.heroku.com

Certificate Authority Authorization (CAA)

No CAA policy is published for this domain — any certificate authority may issue for it.

This certificate has been served since Sep 15, 2026.

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Uptime

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DNS changes

We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.

TLS certificate

We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.

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