# How to Fix the “521: Web Server Is Down” Error

> Canonical: https://jethost.com/kb/fix-error-521-web-server-is-down/ · Last modified: 2026-10-22T09:56:14+00:00

Seeing **“Error 521: Web server is down”**? This is a **Cloudflare** error – it means Cloudflare reached your domain but couldn’t connect to your origin server behind it. Your site isn’t necessarily gone; usually the connection between Cloudflare and your host is being refused. This guide shows the common causes and fixes.

## What Error 521 means

521 appears only when your domain is proxied through Cloudflare. Cloudflare is up, but your origin server either refused the connection or is unreachable. The fix is almost always on the origin (hosting) side – not Cloudflare.

## Common causes and fixes

- **The server is down or overloaded** – check if your site loads directly (without Cloudflare). If your hosting is having an issue, contact support.
- **Cloudflare’s IPs are blocked** – a firewall or security plugin on the server may be blocking Cloudflare. Make sure Cloudflare’s IP ranges are allowed.
- **Wrong origin IP** – the A record in Cloudflare must point to your correct JetHost server IP. Confirm it in your [DNS records](https://jethost.com/kb/how-to-manage-dns-records-at-jethost/).
- **SSL mode mismatch** – if Cloudflare SSL is set to “Full” but the origin lacks a valid certificate, the connection can fail. Make sure your [SSL certificate](https://jethost.com/free-ssl-certificate/) is active.

## Quick test: pause Cloudflare

To confirm it’s a Cloudflare-to-origin issue, temporarily pause Cloudflare (in Cloudflare: **Overview → Advanced Actions → Pause Cloudflare on Site**) and reload. If the site works directly, the problem is the connection between Cloudflare and your host – focus on the firewall/IP and SSL points above.

## JetHost Experts Tip

If pausing Cloudflare fixes it instantly, don’t leave it paused – the real fix is allowing Cloudflare’s IPs on your server firewall. Open a ticket and we’ll whitelist them for you.

## Need more help?

Still seeing Error 521? Open a ticket through **Client Area → Support** – tell us if the site loads with Cloudflare paused, and we’ll pinpoint the cause fast.