NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED
The certificate is not logged in Certificate Transparency
Seen in Chrome, Edge, Brave
The certificate is from a public CA but doesn't carry the Certificate Transparency proofs (SCTs) Chrome requires.
Common causes
- The CA issued the certificate without embedding SCTs from enough trusted CT logs.
- The SCTs come from CT logs that Chrome no longer trusts.
- A server or CDN is configured to deliver SCTs via TLS or OCSP but stopped sending them.
How to fix it
- Reissue the certificate from a CA that embeds SCTs (all major public CAs do by default).
- Search crt.sh for the certificate to see whether it was logged.
- If you deliberately issued an unlogged certificate, reissue it with logging enabled; Chrome only exempts certificates from locally installed private CAs.
Got a different message? Paste it into the error explainer.
Related errors
- NET::ERR_CERT_DATE_INVALID · The certificate has expired or is not yet valid
- NET::ERR_CERT_AUTHORITY_INVALID · The certificate isn't issued by a trusted authority
- SEC_ERROR_UNKNOWN_ISSUER · Firefox doesn't recognise the certificate's issuer
- NET::ERR_CERT_COMMON_NAME_INVALID · The certificate doesn't cover this name
- ERR_SSL_PROTOCOL_ERROR · The secure connection failed during the handshake
- ERR_SSL_VERSION_OR_CIPHER_MISMATCH · No TLS version or cipher in common
- You cannot visit this site right now because the website uses HSTS · HSTS blocks the bypass of a certificate error
- NET::ERR_CERT_REVOKED · The certificate has been revoked by its issuer
- NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM · The certificate is signed with an insecure algorithm
- NET::ERR_CERT_INVALID · The certificate is malformed or breaks platform rules
- ERR_SSL_UNRECOGNIZED_NAME_ALERT · The server has no site configured for this hostname
- ERR_SSL_OBSOLETE_VERSION · The site uses an outdated TLS version