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How to Fix ERR_SSL_PROTOCOL_ERROR in Chrome

2 min read •
Beginner SSL Error Chrome HTTPS

Chrome shows: "This site can't provide a secure connection. [website] uses an unsupported protocol. ERR_SSL_PROTOCOL_ERROR."

This means your browser and the website's server could not agree on how to encrypt the connection. They could not find a common SSL/TLS protocol version to use.

Fix 1: Check the URL

Make sure the URL starts with https:// not http://. If the site does not support HTTPS at all, try http:// instead.

Also check for typos — https://gogle.com will give an SSL error.

Fix 2: Check Your Date and Time

SSL certificates are time-sensitive. If your clock is wrong, certificates look invalid:

Windows: Settings → Time & Language → toggle "Set time automatically" off and on

Mac: System Settings → General → Date & Time → Set Automatically

Fix 3: Clear SSL State (Windows)

  1. Search for Internet Options in Start menu
  2. Go to Content tab
  3. Click Clear SSL State
  4. Restart browser

Fix 4: Clear Browser Cache

Press Ctrl + Shift + Delete → "All time" → check "Cached images and files" → Delete

Fix 5: Disable QUIC Protocol in Chrome

Chrome's experimental QUIC protocol can cause SSL issues:

  1. Type chrome://flags/#enable-quic in address bar
  2. Set Experimental QUIC protocol to Disabled
  3. Restart Chrome

Fix 6: Disable Browser Extensions

Extensions (especially VPN, proxy, and security extensions) can interfere with SSL:

  1. Go to chrome://extensions/
  2. Disable all extensions
  3. Try the site
  4. If it works, re-enable extensions one by one to find the culprit

Fix 7: Disable Antivirus HTTPS Scanning

Many antivirus programs intercept HTTPS connections:

  • Avast: Settings → Protection → Core Shields → Web Shield → disable HTTPS scanning
  • Kaspersky: Settings → Network Settings → disable "Scan encrypted connections"
  • Bitdefender: Protection → Online Threat Prevention → disable "Encrypted web scan"

Fix 8: Update Your Browser

Old browsers do not support modern TLS versions:

  • Chrome: Menu → Help → About Chrome → Update
  • Firefox: Menu → Help → About Firefox → Update
  • Edge: Menu → Help and Feedback → About Edge

Fix 9: Try Another Browser

If Chrome gives the error but Firefox works, the issue is Chrome-specific (cache, extension, or flag). Reset Chrome settings: Chrome Settings → Reset settings → Restore defaults

Fix 10: Check the Server (Website Owners)

Test your SSL configuration with our SSL Server Test. Common server-side causes:

  • TLS 1.0/1.1 only — modern browsers require TLS 1.2+. Update your server config
  • Weak cipher suites — browsers reject insecure ciphers
  • Misconfigured certificate — wrong domain, expired, or missing chain
  • HTTP/2 with old SSL — incompatible combination

Check your HTTPS setup with our HTTPS Redirect Tester.

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