Check a website's SSL certificate
In short
Enter a website address and we check its SSL certificate: when it expires, who issued it, which names it covers and whether browsers trust it.
What we check
- Validity: from when until when the certificate works and how many days are left.
- Names: whether the certificate covers the address you entered. Check the address with www and without it separately, because the certificate must cover every address of the site.
- Trust: whether browsers trust the issuer (the list of trusted issuers that Firefox also uses) and whether the server sends the intermediate certificate.
- Details: issuer, key type, connection version (TLS) and the server address.
How to read the result
A green result means everything is fine. Yellow means it is time to renew the certificate or the server does not send the intermediate certificate: the site works, but it is worth fixing. Red means browsers show visitors a warning instead of the site. We explain the error codes on the page “Your connection is not private”.
It is worth renewing a certificate after two thirds of its validity. For a 90-day Let's Encrypt certificate, that is about a month before it expires. You can generate a new certificate for the same names in the generator.
What happens to the address you enter
The freessl.pl server connects to the site on port 443 and reads the certificate the site shows to every visitor. We only connect to public addresses. For statistics we keep the checked domain, the time and the result for 30 days, without your IP address and without linking them to an account. The result has its own address, e.g. freessl.pl/en/check-certificate/example.com, which you can send to someone; that page is not shown in search engines, and the domain in the address also stays in the server logs (for up to 7 days).
Without our tool
You can also see the expiry date in the browser itself or with the openssl command: see How to check a certificate's expiry date.