"This site can't provide a secure connection": how to fix it

Chrome shows this when the secure handshake with the server fails before any page loads. It often comes with ERR_SSL_PROTOCOL_ERROR. If it is your own site, the fault is usually the server's certificate setup.

If you are visiting someone else's site

  1. Check the date and time on your device. A wrong clock breaks every secure connection.
  2. Try another network, such as your phone's data. Some office and public networks break secure connections.
  3. Turn off antivirus "HTTPS scanning" or a VPN for a minute and retry.

If it is your own site

  1. Is port 443 answering with a certificate at all? A server that only listens on plain http, or answers http on port 443, gives this exact error. Install a certificate (Let's Encrypt is free) and make sure the server is set up for https on 443.
  2. Does the certificate cover this name? A certificate for example.com does not cover www.example.com unless both are listed.
  3. Using Cloudflare? Set SSL mode to Full, not Flexible, once your server has a certificate. A brand new domain on Cloudflare can take up to 24 hours to get its certificate.
  4. Old protocol settings. Servers that only offer TLS 1.0 or 1.1 are refused by current browsers. Allow TLS 1.2 and 1.3.

Paste your address into the free check on this site. It tells you in a minute whether the certificate, the name or the protocol is the problem.

Want the rest of your site checked after it is back? Run a free 40-point check at tinkeraudit.com.