Chrome ERR_SSL_PROTOCOL_ERROR — What It Means

Seeing ERR_SSL_PROTOCOL_ERROR in Chrome? This means Chrome and the server failed to negotiate a secure TLS connection. Learn what causes it and how to fix it.

Does this happen on one site or many?

One specific website

That site has a misconfigured or expired SSL certificate. It's a server-side problem.

Next step: Do not click 'Proceed anyway'. Try the site again in 24–48 hours, or contact the site owner. You can also try it on mobile data to confirm it's not network-specific.

Most or all HTTPS sites

Your system clock is wrong, or a security tool is intercepting SSL connections.

Next step: Check your date and time settings first (right-click clock → Adjust date/time). If that's correct, temporarily disable your VPN or antivirus to test.

Only after installing something new

A VPN, antivirus, or proxy is intercepting SSL and causing protocol mismatches.

Next step: Temporarily disable the most recently installed security software and reload the page. If it works, that tool needs to be configured to trust HTTPS traffic.

Frequently asked questions

Is ERR_SSL_PROTOCOL_ERROR the same as an SSL certificate error in Chrome?
No. They are different errors with different causes. An SSL certificate error (such as NET::ERR_CERT_AUTHORITY_INVALID) means Chrome does not trust the certificate the website is presenting. ERR_SSL_PROTOCOL_ERROR means Chrome and the server could not agree on a compatible TLS protocol version to use — the handshake failed before the certificate was even evaluated.
Why does ERR_SSL_PROTOCOL_ERROR only happen on one specific site?
If the error is limited to one site, the problem is almost certainly on the server's side. That server likely runs an outdated TLS configuration — for example, only supporting TLS 1.0 or 1.1, which Chrome disabled in 2022. Servers that have not been updated to support TLS 1.2 or 1.3 will cause this error in modern Chrome versions.
Could my antivirus be causing ERR_SSL_PROTOCOL_ERROR?
Yes, this is a common cause. Many antivirus products intercept HTTPS connections by acting as a proxy to scan encrypted traffic. If their SSL interception module uses an outdated TLS version or a self-signed certificate Chrome does not trust, ERR_SSL_PROTOCOL_ERROR can appear. Temporarily disabling HTTPS scanning in your antivirus settings — not the full antivirus — is a reliable test.
Will clearing Chrome's SSL state fix ERR_SSL_PROTOCOL_ERROR?
It can help if Chrome has cached a bad SSL session for a site. Go to Chrome Settings → Privacy and Security → Security → Manage Certificates, then use your operating system's certificate manager to clear the SSL cache. On Windows, you can also clear the SSL state through Internet Options → Content → Clear SSL State. This forces Chrome to start a fresh TLS handshake with the server.
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