Guides

HTTP error codes, explained

What each status code actually means, who is at fault, and how to tell a broken site from a broken connection.

15 articles

Cloudflare Error 524: A Timeout Occurred, what it means and how to fix it

A 524 means Cloudflare reached your origin and waited 100 seconds for a response that never came. The network is fine; something behind that URL is too slow. How to find it.

7 min · Aug 8, 2026

What does HTTP 404 Not Found actually mean? (And when it's not your fault)

A 404 means the server answered and told you the page doesn't exist. That is very different from a site being down. How to tell a dead link from a dead site, and what to fix in each case.

6 min · Aug 8, 2026

HTTP 400 Bad Request: what it means and how to fix it

A 400 says the server could not parse your request at all. It is almost always the client's fault, and the usual suspects are cookies, headers, and URL encoding. How to find which.

5 min · Aug 8, 2026

HTTP 401 vs 403: unauthorized, forbidden, and which one you're actually seeing

401 means the server does not know who you are. 403 means it knows and says no. The distinction tells you whether to log in, get permissions, or stop trying.

5 min · Aug 8, 2026

HTTP 408 Request Timeout: what it means and why you rarely see it

A 408 means the server gave up waiting for your request to finish arriving. It is rare, easily confused with 504, and usually points at the network between you and the origin.

5 min · Aug 8, 2026

Cloudflare Error 523: Origin Is Unreachable, what it means and how to fix it

A 523 means Cloudflare could not route to your origin server at all. Usually a DNS record pointing at the wrong IP, a dead server, or a firewall that stopped answering Cloudflare specifically.

6 min · Aug 8, 2026

What does HTTP 500 Internal Server Error actually mean?

What a 500 Internal Server Error means, how it differs from 502, 503, and 504, the usual causes, and what users and site owners can each do about it.

6 min · Jul 17, 2026

What does HTTP 403 Forbidden actually mean? Blocked vs broken

HTTP 403 Forbidden means the server understood your request and refused it. How to tell an auth problem from a WAF or bot block, and what to do for each cause.

6 min · Jul 17, 2026

Why your AI API keeps returning 429 (and how to stop it)

A 429 from OpenAI, Anthropic, or Google isn't an outage, it's a rate limit. What actually triggers RPM/TPM caps, how to back off correctly, and how to tell a limit apart from a real outage.

6 min · Jul 13, 2026

HTTP 502 Bad Gateway: what it actually means and how to fix it

What 502 means, how it differs from 503 and 504, the half-dozen things that actually cause it, and how to diagnose one as either a user or an operator.

7 min · Apr 27, 2026

HTTP 504 Gateway Timeout: what causes it and how to fix it

504 vs 502 vs 408 vs Cloudflare 524, what each one means, what actually causes a 504 in production, and how to diagnose one fast.

7 min · Apr 27, 2026

What does HTTP 503 Service Unavailable actually mean?

The difference between 503 and 500, 502, 504, what each code means, what causes 503 specifically, and how to diagnose one in under a minute.

4 min · Apr 23, 2026

Cloudflare Error 1020 Access Denied: what it means and how to fix it

Error 1020 is a deliberate block by the site owner's Cloudflare firewall, not an outage. Here's how to diagnose why you're blocked and what to do next.

6 min · Apr 21, 2026

HTTP 429 Too Many Requests: what triggers it and how to handle it

What 429 means, how it differs from 503 and 1015, when servers send it, and the right way to back off without making the problem worse.

5 min · Apr 18, 2026

Cloudflare Error 1015: what "You are being rate limited" actually means

1015 is a Cloudflare-edge rate limit, not an outage. Here's why it triggers, how it differs from 1020 and 429, and what to do as a user or site owner.

5 min · Apr 17, 2026

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