Chrome, Edge

ERR_SSL_PROTOCOL_ERROR

The TLS handshake failed before any page could load. The server answered, but the two sides could not agree on a secure connection.

What causes it

The server offers only obsolete protocols (TLS 1.0/1.1) that modern browsers refuse.
A misconfigured or incomplete certificate chain.
Antivirus software intercepting HTTPS with its own certificate.
Wrong system clock, which makes valid certificates look invalid.

If you are the visitor

Check your device clock and timezone.
Disable HTTPS scanning in your antivirus and retry.
Try another browser to see whether it is device-specific.

If it is your website

Enable TLS 1.2 and 1.3 and disable everything older.
Install the full certificate chain, not just the leaf certificate.
Run an SSL check to see what the server actually presents.

Find out whether the site is down for everyone

A live check from our server shares nothing with your network — it settles the question in seconds.

Run a live check

Other connection errors

ERR_CONNECTION_REFUSED DNS_PROBE_FINISHED_NXDOMAIN ERR_NAME_NOT_RESOLVED ERR_CONNECTION_TIMED_OUT NET::ERR_CERT_AUTHORITY_INVALID NET::ERR_CERT_DATE_INVALID NET::ERR_CERT_COMMON_NAME_INVALID ERR_TOO_MANY_REDIRECTS ERR_EMPTY_RESPONSE ERR_CONNECTION_RESET 503 Service Unavailable 502 Bad Gateway This site can't be reached