Cloudflare error 523: origin is unreachable

Updated 11 October 2026

Short answer

Error 523 means Cloudflare can't reach your server's address at all. It's not that the server is slow or refusing: there's no path to it. By far the most common reason is that the IP address in your Cloudflare DNS records is wrong, for example after a server move or a host changing your IP. Check your DNS records against your host's current IP address.

What's the problem

Visitors see "Error 523: Origin is unreachable" on a Cloudflare page.

Why it happens

  • Wrong IP address in DNS. The server moved, or the host changed its IP, and Cloudflare still points at the old one.
  • The host's network is down, or the server has no public network connection.
  • A routing problem between Cloudflare and your host.

How to fix it

  1. Find your server's current IP address in your hosting dashboard.
  2. Compare it with the A (and AAAA) records in your Cloudflare DNS settings. Update them if they differ.
  3. If you recently moved hosts, make sure every record (including www) points at the new server.
  4. If the IP is correct, contact your host with the error and the time. Their network may be down.

What Preventionlabs checks

One click runs the full report on your domain. For this problem it shows whether your site loads, how fast, and where its redirects go; uptime checked every 5 minutes, with an email when the site goes down and when it is back. With Cloudflare connected, it also shows which pages returned server errors (5xx) to visitors, and when; your SSL mode and the other settings that commonly cause this; which requests the firewall blocked, by Cloudflare's own rule names; recent deploys and account changes, with their times; DNS changes in the last 7 days.

Run your free report

Your first report is free, no card needed. Then A$50 a month, up to 10 domains. Read-only: it never changes anything.

Sources

  1. Cloudflare: Error 523official docsThis typically occurs when a network device between Cloudflare and the origin web server does not have a route to the origin's IP address.

Related

Cloudflare error 522: connection timed out Error 522: Cloudflare couldn't connect to your server in time. The server is overloaded or offline, or a firewall is silently dropping Cloudflare. DNS error A DNS error means the name couldn't be turned into an address. Check whether it fails everywhere or only on your network, then check the domain's records. Cloudflare error: what it means and how to fix it A Cloudflare error page almost always means Cloudflare is fine but couldn't get a proper answer from your own server. The number says which part failed. Domain not working Check three things in order: the domain hasn't expired, its nameservers are the ones you expect, and its DNS records point at your current host.

Preventionlabs is independent and not affiliated with Cloudflare. Product names are used only to describe the problem.

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