Certificate Viewer
Open an SSL/TLS certificate and read its details — issuer, validity, domains and more.
Reading a certificate's details
An SSL/TLS certificate is the credential that secures HTTPS, and its details are encoded rather than plainly readable. This opens a certificate and lays out what it contains: who it was issued to and by, when it is valid from and until, which domains it covers, and its technical particulars — so you can inspect a certificate you are configuring or troubleshooting.
Paste or open a certificate and its details are displayed.
The details that matter most
A few fields are where certificate problems usually live. The validity dates are the classic one — an expired certificate breaks HTTPS for every visitor, and it is one of the most common and avoidable outages. The covered domains matter because a certificate only secures the exact names it lists, so a mismatch throws a browser warning. The issuer tells you whether it is from a trusted authority. Being able to read these directly is how you confirm a certificate is set up correctly, diagnose a browser security warning, or check when one is due to be renewed. It is read in your browser, so a certificate is not uploaded anywhere.
Questions & answers
What details does it show?
The issuer, the subject and covered domains, the validity dates, and the certificate's technical particulars.
What usually causes certificate problems?
Expiry — an expired certificate breaks HTTPS for everyone — and domain mismatches, where the certificate does not cover the name being used.
Is my certificate uploaded?
No. It is read in your browser.