---
title: "523 Origin Is Unreachable"
canonical: "https://lemwatch.com/http-status-codes/523"
category: "server-error"
last_verified: "2026-08-11"
source: "https://lemwatch.com"
---

# HTTP 523 Origin Is Unreachable

**Summary** — Cloudflare could not reach the origin server, likely due to DNS issues.

## What it means

HTTP 523 is a Cloudflare-specific error meaning Cloudflare cannot resolve the origin server's DNS or route to its IP address.

## Common causes

- Incorrect origin IP in Cloudflare settings
- DNS resolution failure
- Origin server IP changed
- Network routing issue

## How to fix

- Verify the origin IP in Cloudflare DNS settings
- Check that DNS records are correct
- Ensure origin server is accessible from outside

## SEO impact

Complete site outage through Cloudflare. Will be treated as downtime by search engines.

## Monitoring tip

LemWatch monitors DNS resolution as part of its checks and can detect when origin IP changes cause reachability issues.

**Related:** [521](https://lemwatch.com/http-status-codes/521.md), [522](https://lemwatch.com/http-status-codes/522.md), [502](https://lemwatch.com/http-status-codes/502.md)

_Canonical HTML page: https://lemwatch.com/http-status-codes/523_