Skip to content
TabBench

HTTP Status Code Lookup

Search every HTTP status code, including nginx and Cloudflare ones. See what it means, when it appears, how to fix it and whether it is safe to retry.

Runs in your browser. Nothing you add is uploaded.

What the HTTP Status Code Lookup does

Every HTTP response starts with a three-digit status code, and knowing what it means is the fastest way to debug a failing page or API call. This lookup covers every code in the official registry, from 100 Continue to 511 Network Authentication Required, plus the non-standard codes that show up in real logs, such as nginx's 499 and Cloudflare's 520 to 530. Each entry says what the code means, when a server sends it, how to fix it if it is an error, and whether the request is safe to retry.

How to look up an HTTP status code

  1. Type the code (for example 404) or a word that describes the problem, such as “timeout”, “redirect” or “rate limit”.
  2. Filter by class (1xx to 5xx) to browse one family of codes, or use the quick buttons for the codes people look up most.
  3. Select a code to open its details: when it appears, how to fix it, related headers and similar codes.
  4. Follow a “See also” link to compare neighbours, for example 301 against 308.
  5. Use “Copy link to this code” to share a direct link to an entry with a colleague.

The HTTP Status Code Lookup runs entirely in your browser — nothing you enter is uploaded, stored, or logged.

When to use it

Debugging a failing API call

A 401, 403 and 404 look similar in a log but mean different things: missing credentials, refused access and a wrong URL. The fix section tells you what to check first for each.

Choosing the right code for your own API

Returning 200 for everything hides problems from clients. Use the details to pick precisely: 201 after creating, 204 after deleting, 409 for conflicts, 422 for validation errors and 429 when rate limiting.

Fixing redirects for SEO

301 and 308 tell search engines a page moved for good; 302 and 307 say it is temporary. Picking the wrong pair can leave old URLs ranking or lose link value.

Good to know

  • 4xx means the client needs to change something; 5xx means the server failed. Retrying a 4xx unchanged will not help; retrying a 502, 503 or 504 after a delay often does.
  • A 429 or 503 should come with Retry-After. Honour it instead of retrying immediately.
  • 404 and 410 both mean “not here”, but 410 tells search engines the page is gone for good and is dropped a little faster.
  • A 502 or 504 from nginx, Cloudflare or a load balancer usually means your application is down or slow, not the proxy itself.
  • Status codes are sent by servers and are not always honest. Some sites return 200 with an error page. Check the body too.

Guides that use this tool

Frequently asked questions

What is the difference between 401 and 403?

401 Unauthorized means the request has no valid credentials: log in or send a correct token. 403 Forbidden means the server knows who you are, or does not care, and still refuses. Sending the same credentials again will not help with a 403.

Should I use 301 or 302 for a redirect?

Use 301 (or 308) when a page has moved for good, so browsers and search engines update their records. Use 302 (or 307) for a temporary move, such as sending a signed-out visitor to a login page.

Are the non-standard codes like 499 official?

No. They are defined by a specific server or service, such as nginx or Cloudflare, and they are marked as such here. They are real codes that appear in logs and error pages but are not part of the HTTP standard.

What is the difference between 500, 502, 503 and 504?

500 is an unexpected error inside the application. 502 means a proxy or gateway received an invalid answer from the application behind it. 503 means the service is temporarily unavailable, for example overloaded or in maintenance. 504 means the proxy waited too long for an answer.

What does 418 I'm a teapot mean?

It comes from an April Fools' RFC for a coffee-pot control protocol. It is reserved in the registry, and a few servers return it to reject automated traffic or as a joke. You are unlikely to see it on a normal site.

Which codes can a cache store automatically?

By default 200, 203, 204, 206, 300, 301, 308, 404, 405, 410, 414 and 501 can be cached without extra headers. Most other codes need explicit freshness information such as Cache-Control.

Related tools