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 planplus.co.jp

Valid
Issued by (CA)
Let's Encrypt
Subject
planplus.co.jp
Valid from
Jul 17, 2026
Valid until
Oct 15, 2026 (34 days remaining)
Public key
RSA 2048-bit
Serial
050FA7368BD96ADCF5502E006BD5B513AE6F
SHA-256 fingerprint
B2:9F:78:56:E9:21:6F:42:6E:E3:ED:66:FD:2B:3A:0D:72:E0:39:0B:0D:4E:0A:0D:91:1B:80:61:EA:03:AF:95
Chain
YR1 → Root YR → ISRG Root X1
Subject Alternative Names (2)
planplus.co.jp, www.planplus.co.jp

Certificate Authority Authorization (CAA)

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

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This is today's certificate. Turn on monitoring and we'll watch planplus.co.jp continuously, notifying you the moment anything moves across all three signals:

Uptime

We visit the site from multiple regions worldwide and email you within minutes if it goes down, with a per-region breakdown so a real outage stands out from a regional blip.

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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