---
title: "523 Origin Is Unreachable — what it means and how to fix it"
description: "Cloudflare cannot route to the origin server at all — as far as the network is concerned, it does not exist. What causes an HTTP 523, what to try as a visitor, and what to check if it is your own site."
url: https://atoneplace.net/error/523/
site: "At One Place"
---

# HTTP 523 — Origin Is Unreachable

**HTTP 523: Origin Is Unreachable**

Cloudflare cannot route to the origin server at all — as far as the network is concerned, it does not exist.

## What 523 actually means

A Cloudflare code, not standard HTTP. It sits one layer below 521 and 522: the problem is not that the server refused or timed out, but that Cloudflare could not reach the address at all. The usual explanation is a DNS record pointing at an IP that is no longer yours, or that never was — after a server migration where the record was not updated, for example.

## Common causes

- The origin IP address in DNS is wrong, stale, or belongs to a decommissioned server
- A server migration where the DNS record was not updated
- BGP or routing problems between Cloudflare and the origin network
- The origin host powered off or terminated
- A CNAME chain resolving to something unroutable

## If you're just trying to view the page

1. Nothing you can do — the site's origin address is unreachable from Cloudflare
2. Try again later, and report it to the site owner with the Ray ID

## If it's your site

1. Check that the A/AAAA record in Cloudflare's DNS matches the current origin IP address
2. Confirm the origin host is running and has the IP you think it has
3. Test routing to the origin from an external network with `mtr` or `traceroute`
4. If you use a CNAME to another provider, verify that chain resolves to something routable

## Reference

- **Status code:** 523
- **Reason phrase:** Origin Is Unreachable
- **Category:** 5xx — Server Error
- **Cacheable by default:** No

## Common questions

### What does HTTP 523 mean?

Cloudflare cannot route to the origin server at all — as far as the network is concerned, it does not exist. A Cloudflare code, not standard HTTP. It sits one layer below 521 and 522: the problem is not that the server refused or timed out, but that Cloudflare could not reach the address at all.

### How do I fix a 523 error?

Nothing you can do — the site's origin address is unreachable from Cloudflare

### Is 523 a client error or a server error?

523 is in the 5xx range, which means server error. The request was acceptable but the server could not fulfil it, so retrying later can succeed.

## Related pages

- [500 Internal Server Error](https://atoneplace.net/error/500/)
- [502 Bad Gateway](https://atoneplace.net/error/502/)
- [503 Service Unavailable](https://atoneplace.net/error/503/)
- [504 Gateway Timeout](https://atoneplace.net/error/504/)
- [524 A Timeout Occurred](https://atoneplace.net/error/524/)
- [521 Web Server Is Down](https://atoneplace.net/error/521/)
- [522 Connection Timed Out](https://atoneplace.net/error/522/)
- [520 Web Server Returned an Unknown Error](https://atoneplace.net/error/520/)
- [525 SSL Handshake Failed](https://atoneplace.net/error/525/)
- [526 Invalid SSL Certificate](https://atoneplace.net/error/526/)
- [530 Origin DNS Error](https://atoneplace.net/error/530/)
- [501 Not Implemented](https://atoneplace.net/error/501/)

## Sources

- Hypertext Transfer Protocol (HTTP) Status Code Registry — IANA (https://www.iana.org/assignments/http-status-codes/)
- RFC 9110: HTTP Semantics — IETF (https://www.rfc-editor.org/rfc/rfc9110.html)