SSL Certificate Checker
Check the TLS / SSL certificate expiry of one or many hosts at once. Each host is looked up in the public certificate-transparency records via the Certspotter API, direct from your browser — fast and handles many hosts at once. It reports recorded certificates, which may not be the one the server is actually serving right now.
| Host | Issuer | Valid from | Expires | Days left | Status |
|---|
How To Use
- Paste one host per line (e.g.
example.com). Schemes, paths and ports are stripped automatically. - Click Check expiry for a fast Certspotter batch lookup (most recently issued, non-revoked cert per host).
- Read the Days left and Status badges: Expiring soon = under 30 days, Expired = past expiry.
Usage Example
Input:
example.com example.org
Example rows after a Certspotter expiry check (dates vary by lookup):
Host Issuer Expires Days left Status example.com Sectigo RSA DV CA 2026-12-02 220 Valid example.org Let's Encrypt E5 2026-09-25 24 Expiring soon
Certspotter reports the most recently issued non-revoked certificate for each host.
Frequently Asked Questions
Why does it return a recently issued certificate?
Certspotter reads the certificate-transparency logs, which hold every certificate that has been issued for a host — including old ones that are already superseded. To best reflect what a site likely uses now, this tool picks the most recently issued non-revoked certificate (a renewal is issued right before it is deployed).
Is this a live check, or an approximation?
It is an approximation, not a live handshake. A CT log records that a certificate was issued, not that the server is already serving it. Renewals are usually issued shortly before they are switched on, so the most recently issued certificate is the closest guess to what a site runs today — but if a site has just renewed and not yet swapped it in, the result can differ by up to a few days from the certificate currently being served.
What do the status badges mean?
Valid = more than 30 days until expiry; Expiring soon = under 30 days; Expired = already past the expiry date; Unavailable = no parseable expiry was returned; Error = the lookup failed (timeout, rate limit, or no certificate found) — other hosts still complete.
Does this upload my hosts?
Yes — checking a certificate requires asking the Certspotter API, so the hosts you type are sent there. No server in this project stores your lookups, and nothing else leaves your browser.
Does it need a proxy or an API key?
No. The check runs directly from your browser against the Certspotter API, which allows CORS requests, so no server-side proxy, setup, or extension is required.