Cloudflare Error 521: web server is down

I have 3 Wordpress sites running on the same Ubuntu machine. I noticed that my websites are not working today. When I checked Cloudflare, I saw that it could not access the server from 443 ports.

I can access the server IP address when I enter the browser, but the domain name does not work.

What caused this?

Submit an answer

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Sign In or Sign Up to Answer

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Even after I add ipv4s on i still get the same error please help.

Error 521 occurs because the origin web server refuses a connection from Cloudflare. More specifically, Cloudflare tried to connect to your origin server on port 80 or 443 but received a connection refused error

Hi there @volkanalkilic,

It sounds like that there might be an issue with your Apache or Nginx web server (depending on which one you are using), I would recommend going through these answers here in order to get some more information regarding the actual problem:

  • If you are using Apache:

  • If you are using Nginx:

Another thing that could be causing the issue is if the firewall on your Droplet is blocking Cloudflare if this is the case you need to make sure that you whitelist CloudFlare’s IP ranges so that this does not happen in the future.

You can find Cloudflare’s IP rages here:

Hope that this helps! Regards, Bobby