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HTTP status code reference

Reference & converters

Search common HTTP response codes with class and meaning.

Updated

Search status codes

Matches (20)

CodeTitleGroupDescription
100Continue1xxRequest headers received; continue request body.
200OK2xxRequest succeeded.
201Created2xxResource created successfully.
204No Content2xxRequest succeeded with no response body.
301Moved Permanently3xxResource permanently moved to new URL.
302Found3xxTemporary redirect.
304Not Modified3xxCached resource still valid.
400Bad Request4xxMalformed request syntax.
401Unauthorized4xxAuthentication required.
403Forbidden4xxServer understood request but refuses it.
404Not Found4xxResource not found.
405Method Not Allowed4xxHTTP method not allowed for resource.
409Conflict4xxRequest conflicts with current state.
410Gone4xxResource permanently removed.
422Unprocessable Content4xxSemantically invalid request payload.
429Too Many Requests4xxRate limit exceeded.
500Internal Server Error5xxGeneric server-side failure.
502Bad Gateway5xxInvalid upstream response.
503Service Unavailable5xxServer temporarily unavailable.
504Gateway Timeout5xxUpstream response timeout.

Quick start

How to use HTTP status reference

Search status codes by number, title or error type.

  1. Step 1
    Search code

    Type code like 404 or keyword like timeout.

  2. Step 2
    Read meaning

    Inspect category and practical interpretation.

  3. Step 3
    Apply fix

    Use result while debugging API or backend responses.

In-depth guide

HTTP status codes: what each response really means

Every HTTP response carries a three-digit status code that summarises what happened. Knowing the families — and the handful of codes you meet daily — turns a vague "it broke" into a precise diagnosis. This reference lets you search any common code and read what it means in real API and web workflows.

The five families

  • 1xx informational — request received, continuing (rarely seen directly).
  • 2xx success — it worked: 200 OK, 201 Created, 204 No Content.
  • 3xx redirection — go elsewhere: 301 permanent, 302 temporary, 304 Not Modified.
  • 4xx client error — your request was wrong: 400, 401, 403, 404, 429.
  • 5xx server error — the server failed: 500, 502, 503, 504.

Codes people mix up

401 Unauthorized actually means unauthenticated — log in. 403 Forbidden means you are authenticated but not allowed. 502 Bad Gateway is an upstream server returning garbage to a proxy; 504 Gateway Timeout is the upstream not answering in time. 429 Too Many Requests means you hit a rate limit — back off and check the Retry-After header.

How to use this reference

Type a code, title or keyword to filter the list. Pair the status with the response body and your server logs: the code tells you the category, the body and logs tell you the exact cause. A 500 with a stack trace in the body is far faster to fix than a 500 alone.

Privacy

This is a static reference — nothing you type is sent anywhere. The search runs locally in your browser and no lookups leave the page.

When to use it vs alternatives

Use this tool for quick browser-based work when you need an answer or output immediately. Use a dedicated application or automated workflow when you need bulk processing, approvals, or repeatable production rules.

Common pitfalls

  • Check the result before replacing the original input.
  • Watch for unit, format, encoding, and browser memory limits on large inputs.
  • Keep a copy of important source material until the output is verified.

Frequently asked questions

Does this include all HTTP status codes?

It includes the most commonly used response codes across the 1xx through 5xx families — the ones you actually meet in API and web work.

Can I search by keyword?

Yes. Search matches the code number, the title, the family and the description text.

Is this meant for debugging APIs?

Yes. It is optimised for quick lookups while debugging APIs and backends.

What is the difference between 401 and 403?

401 Unauthorized actually means unauthenticated — you need to log in. 403 Forbidden means you are authenticated but not allowed to access the resource.

What does 429 mean?

429 Too Many Requests means you hit a rate limit. Back off and check the Retry-After header for how long to wait before retrying.

How are 502 and 504 different?

502 Bad Gateway is an upstream server returning an invalid response to a proxy. 504 Gateway Timeout is the upstream server not responding in time.

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