How can I troubleshoot a Cloudflare 521 error?

Troubleshooting a 521 error involves several steps. First, verify your website is not experiencing unusual traffic spikes. Next, check your server's health and resources to ensure it's not overloaded. You can also try temporarily disabling Cloudflare to see if the issue persists, which helps determine if the problem lies with Cloudflare itself. If it's a traffic issue, consider optimizing your website for performance or adjusting Cloudflare's rate limiting settings.