523 Origin Is Unreachable — Causes & Fix
HTTP 523 (Origin Is Unreachable) means Cloudflare cannot reach the origin server at all — often a routing or DNS problem pointing to the wrong/unreachable address.
- Applies to
- Any website or web server (HTTP standard)
- Time to fix
- 15 minutes – 2 hours
What it means
Causes include an incorrect origin IP/DNS record, the origin being offline, or a network/routing failure. This is a Cloudflare-specific status code (not part of the HTTP standard). Cloudflare returns it when it sits in front of a site and has a problem reaching or getting a valid response from the origin (your) server — so the fix is almost always at the origin, not with the visitor.
Symptoms
- Cloudflare "Error 523" page
- Site unreachable behind Cloudflare
How to fix it
- 1
Verify the origin address
1. As the operator: confirm Cloudflare's DNS points to the correct, reachable origin IP.
- 2
Check routing/health
1. Ensure the origin is online and reachable from the internet.
Frequently asked questions
What causes Error 523?
Cloudflare can't reach your origin — usually a wrong origin IP/DNS record or the origin being offline. Verify the DNS target and server status.
Last updated July 20, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.