How to Fix Error 521 on Cloudflare Websites

Error 521 occurs when the origin server refuses Cloudflare’s connection request, causing the website to appear down.

Understanding Error 521

Error 521, or “Error 521: Web server is down,” is a connection time-out error that indicates the website is experiencing a server-side problem. This error commonly affects Cloudflare-enabled websites and occurs when the origin server rejects Cloudflare’s connection request.

Steps to Fix Error 521

1. Check Whether the Origin Server is Running

Start by ensuring that your server is operational. If there is ongoing maintenance or your hosting provider is experiencing downtime, the server might be blocking IP requests. You can verify the server status using the Terminal with the PING command for Linux or Traceroute for Windows. Alternatively, check your resource usage for CPU and memory limits using the Hostinger hPanel.

If your WordPress site is affected, consider removing unnecessary plugins to reduce the server load. Contact your hosting provider if you lack server access.

2. Test the Connection to the Server

Ensure that your server’s firewall does not block Cloudflare IP addresses. Check for any rate-limiting IP requests from Cloudflare’s IP ranges. You can test the server’s connection using a cURL command. Additionally, use the .htaccess file to safelist Cloudflare IP ranges. Hostinger users can easily manage IP access through the IP Manager in hPanel.

3. Check Encryption Settings

Cloudflare encryption modes help connect the CDN with your web origin server. Incorrect settings can cause connection issues. Ensure you’re using the correct SSL/TLS mode in the Cloudflare dashboard. The modes are Flexible, Full, and Strict, each with different requirements and levels of security.

4. Check for Website Issues

If other solutions fail, temporarily disable Cloudflare to diagnose website issues. This process might take a couple of hours but purging the cache can speed it up.

What Causes Error 521?

Several factors can trigger Error 521, such as incorrect server configuration, firewall settings blocking Cloudflare requests, server downtime, or poor encryption settings. Checking error logs can help identify the issue.

Troubleshooting Other Cloudflare Errors

Aside from Error 521, you might encounter Error 520 or Error 522. Error 520 indicates an unknown error from the web server, while Error 522 refers to a connection timeout. Similar troubleshooting steps apply to these errors. For persistent issues, contact your hosting provider or Cloudflare support.

Conclusion

If your website displays “Error 521: Web server is down,” it indicates a connection issue between Cloudflare and your origin server. You can resolve this by ensuring the server is operational, checking firewall settings, selecting the right SSL/TLS mode, and temporarily disabling Cloudflare if needed. For WordPress users, removing high-load plugins can help. Consider Hostinger for reliable support and hosting solutions.

“Error 521” FAQs

How do I prevent “Error 521”?

Ensure your origin server is always operational and verify firewall or security settings to prevent Error 521.

Is “Error 521” common for Cloudflare users?

No, it is relatively rare and typically indicates an issue with the origin server, not Cloudflare’s services.

Do I need to access my server if I encounter “Error 521”?

Yes, you’ll need to troubleshoot the issue on your server or contact your hosting provider for assistance. Hostinger offers customer support to help resolve such errors.

Starter-Pack

Oct 07, 2024
Astari S.
5min Read

Astari is a digital marketing expert, with a focus on SEO and WordPress. She loves to share her wealth of knowledge through her writing, and enjoys surfing the internet for new information when she’s not out in the waves or hiking a mountain. Her mission is to learn something new every day, and she firmly believes that there is no such thing as too much knowledge.

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