Reachability

How to look up what an HTTP status code means

A log or a check returned a number and you need the class. Look it up on HTTP Status Codes.

Ben Fidge · Oct 2026 · 4 min read

HTTP classes: 2xx and 3xx are up, 4xx means the host answered, and 5xx is server-side. — 1xx is informational, 2xx and 3xx are up, a 4xx means the host answered, and 5xx is server-side.

What to run

Use HTTP Status Codes. That page stays in the browser.

How to read the result

1xx informational, 2xx success, 3xx redirect, 4xx client, 5xx server.

The page gives the title, meaning, and a typical cause. It does not fetch your URL.

What to open next

If you have a URL, run Is This Website Down or HTTP Headers to see the live code. Both results are from Cloudflare.

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