Free tool
Check any SSL certificate
See whether a site's certificate is valid, when it expires, who issued it, which names it covers and the full chain, checked from Stockholm.
Checked from Stockholm, Sweden · Free, no sign-up
- Try
Questions
How long is an SSL certificate valid?
Public certificates are valid for at most 398 days, and the limit is falling: 200 days from March 2026, 100 days from March 2027 and 47 days from March 2029. Free certificates from Let's Encrypt last 90 days and are renewed automatically, when the renewal works.
Why does a browser say the certificate isn't trusted?
Usually one of four reasons: it has expired, it was issued for a different name, it's self-signed, or the server doesn't send the intermediate certificate that links it to a trusted authority. The result above names which one.
What is the certificate chain?
The server's certificate is signed by an intermediate authority, which is signed by a root that browsers trust. The server must send its own certificate and the intermediates; the root is already in the browser.
How do I get warned before a certificate expires?
A website monitor on Uptimecheck reads the certificate on every check and reminds you 30, 14, 7 and 1 days before it expires, and on the day itself.
More free tools
All tools- Is it down? Check whether a website answers, how fast, and when its certificate expires. Open tool
- Domain expiry checker Look up a domain's expiry date, registrar and age from the registry's own records (RDAP, or WHOIS where there is none). Open tool
- DNS lookup Ask for any record type and see every answer with its TTL, straight from a resolver, without a cache in between. Open tool
Downtime is obsolete.
Set up your first monitor in under a minute, or look around the live demo first.
14-day free trial · No credit card required