ERR_SSL_VERSION_OR_CIPHER_MISMATCH
ERR_SSL_VERSION_OR_CIPHER_MISMATCH Error
What This Error Means
This error happens when the browser and the server cannot agree on a common encryption protocol (SSL/TLS version) or cipher suite. It's like two people trying to talk but speaking different languages.
Common Causes
- Server is using very old SSL versions (SSLv3, TLS 1.0) that modern browsers have blocked.
- Server is using a cipher suite that the browser considers insecure (e.g., RC4).
- Browser is outdated and doesn't support modern TLS 1.2/1.3.
- QUIC protocol interference.
How to Fix It (For Users)
- 1 Update your browser.
- 2 Check if the site works in other browsers (e.g., Firefox vs Chrome).
- 3 Disable QUIC protocol in Chrome flags.
For Site Owners / Developers
- Disable support for SSLv3, TLS 1.0, and TLS 1.1 on your server.
- Enable TLS 1.2 and TLS 1.3.
- Configure a modern, secure list of cipher suites.
- Use tools like SSL Labs to test your configuration.
When It Is NOT Your Fault
If the server is using obsolete security standards.
Check if this outage affects everyone globally
This error often indicates a wider problem. Use our tool to verify if the site is down for everyone.
Check Website Status →Recommended Tool to Prevent This Error
Get alerted immediately when your SSL certificate expires or your site goes down.