How to check an SSL certificate
- Enter a website name such as example.com.
- Select Check.
- Read the result and any warnings.
About this tool
Enter a website to read its HTTPS certificate. You see who issued it, when it starts and ends, how many days are left, which names it covers, the certificate chain and the TLS version negotiated. Clear warnings tell you if it has expired, is about to, does not match the host, is self-signed, or the server could not prove the chain. Only public websites are checked.
Common questions
How soon should I renew?
Renew at least two weeks before the end date. Many certificate authorities now issue short-lived certificates, so automatic renewal is worth setting up.
What does a name mismatch mean?
The certificate does not list the host you entered, so browsers will warn visitors. Check that the right certificate is installed for that name.
Why does it say the chain could not be verified?
The server may not send its intermediate certificate. Browsers sometimes fill the gap, but other clients will fail.
Is it free to use?
Yes. There's no sign-up, and you can use it as often as you like.
Do I need to install anything?
No. It works in your browser on a computer or a phone.
Is what I enter kept?
It's only used to get your result. Some public answers, such as the branches for a pincode, are kept for a while so the next lookup is quicker, but nothing links them to you.