What the certificate viewer shows
- Names covered (SAN): every domain the certificate is valid for. Browsers only look at this list, not the common name.
- Validity: start and end dates and the total lifetime. Public certificates are limited to 200 days since March 2026.
- Public key and signature: for example ECDSA P-256 or RSA 2048 bits, signed with SHA-256.
- Serial number and fingerprints: unique IDs for the certificate, useful for pinning, revocation and support tickets.
- Validation type: whether the authority checked only the domain (DV), the organisation (OV), or did extended validation (EV).
- Key usage, OCSP, CRL and Certificate Transparency, plus each intermediate certificate the server sends.
How to view a certificate yourself
In the browser
Click the icon left of the address bar, then "Connection is secure" and "Certificate is valid" (Chrome) or "More information" (Firefox).
With openssl
openssl s_client -connect example.com:443 -servername example.com </dev/null | openssl x509 -noout -text
This viewer shows the same information without the command line, and works from any device.
Questions
What's the difference between DV, OV and EV certificates?
They differ in what the authority checked before issuing. DV (domain validated) proves you control the domain; Let's Encrypt only issues DV. OV and EV also verify the organisation. Browsers show the same padlock for all three.
What is a SHA-256 fingerprint?
A hash of the whole certificate. If two fingerprints match, it's exactly the same certificate. Use it to confirm a server is presenting the certificate you installed.
Can I download the certificate?
Yes. "Download the chain as PEM" gives you every certificate the server sends, in order, in the same format as fullchain.pem. It contains only public certificates, never a private key.
Is this certificate viewer free?
Yes. View any public website's certificate as often as you like, within a fair rate limit. Results are kept in memory for 5 minutes, then discarded.