We refer to the SSL Labs rating guide to explain how we calculate grades.
There are a few differences in the way we assign grades:
- SSL Labs assigns a zero score to the certificate inspection portion if there is a domain name mismatch or the certificate is revoked. Certificate View does not assign a zero score for these criteria. However, the certificate score does not affect the overall grade.
- Both SSL Labs and CertView detect the use of legacy 64-bit block ciphers. However, SSL Labs lowers the severity of this vulnerability if it detects that these legacy ciphers are only used with older browsers. Where as Certificate View considers it to be a confirmed Severity 3 vulnerability (regardless of the browser used) and caps the grade to C.