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HTTP Status Codes Reference

A complete HTTP status codes list for web developers. Search, filter, and master REST API status codes with official definitions.

100

Continue

"The server has received the request headers and the client should proceed to send the request body."

1xx SERIES
101

Switching Protocols

"The requester has asked the server to switch protocols and the server has agreed to do so."

1xx SERIES
200

OK

"Standard response for successful HTTP requests. The payload depends on the request method."

2xx SERIES
201

Created

"The request has been fulfilled, resulting in the creation of a new resource."

2xx SERIES
202

Accepted

"The request has been accepted for processing, but the processing has not been completed."

2xx SERIES
204

No Content

"The server successfully processed the request and is not returning any content."

2xx SERIES
301

Moved Permanently

"The request and all future requests should be directed to the given URI."

3xx SERIES
302

Found

"Temporary redirect to a different URI. Used for temporary URL changes."

3xx SERIES
304

Not Modified

"Indicates that the resource has not been modified since the version specified by headers."

3xx SERIES
400

Bad Request

"The server cannot or will not process the request due to an apparent client error."

4xx SERIES
401

Unauthorized

"Authentication is required and has failed or has not yet been provided."

4xx SERIES
403

Forbidden

"The request was valid, but the server is refusing action due to insufficient permissions."

4xx SERIES
404

Not Found

"The requested resource could not be found but may be available in the future."

4xx SERIES
405

Method Not Allowed

"A request method is not supported for the requested resource (e.g., POST on a GET-only route)."

4xx SERIES
408

Request Timeout

"The server timed out waiting for the request from the client."

4xx SERIES
409

Conflict

"Indicates that the request could not be processed because of conflict in the current state."

4xx SERIES
418

I'm a teapot

"The HTCPCP server is a teapot; use this for comedic effect or non-standard errors."

4xx SERIES
429

Too Many Requests

"The user has sent too many requests in a given amount of time (rate limiting)."

4xx SERIES
500

Internal Server Error

"A generic error message, given when an unexpected condition was encountered."

5xx SERIES
502

Bad Gateway

"The server received an invalid response from an upstream server."

5xx SERIES
503

Service Unavailable

"The server is currently down for maintenance or is overloaded."

5xx SERIES
504

Gateway Timeout

"The server did not receive a timely response from the upstream server."

5xx SERIES

Built With Care

Status codes are defined by RFC 9110 and related standards, and the official registry is maintained by IANA. The page groups codes into the standard series 1xx through 5xx, so you can tell at a glance whether a response is informational, successful, a redirect, a client error, or a server error.

HTTP Status Codes

A searchable reference of HTTP status codes with plain-English explanations for every response class, from 1xx informational to 5xx server errors. Look up common codes like 200, 301, 404, and 500, plus edge cases such as 418 and 429, then handle them correctly in your APIs.

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How to Use HTTP Status Codes
  • 1Type a code number such as 404 or 500 into the search box.
  • 2Or search by phrase, like 'Not Found' or 'Gateway'.
  • 3Filter by series using the 1xx through 5xx buttons to focus on one category.
  • 4Read the card for the status phrase and its plain-English meaning.
  • 5Check the series label to classify the response type.
  • 6Apply the correct handling in your application code based on the code's meaning.
Key Features
  • Instant Search: Filter by code number or phrase with live results.
  • Series Filtering: Narrow results to informational, success, redirect, client error, or server error classes.
  • Plain-English Definitions: Each code includes an explanation written for developers.
  • RFC-Aligned: Descriptions follow RFC 9110 and the IANA HTTP status code registry.
  • Notable Edge Cases: Includes 418 and 429 alongside the everyday codes.
  • Color-Coded Categories: Visual indicators make response classes easy to distinguish at a glance.

HTTP Status Codes Specs

Limits

  • Standard 1xx–5xx codes
  • Search and category filter

Formats

  • Output: code, phrase, description

Defaults

  • Full list, no filter

How it works

  • Static reference data

Honest caveats

  • Non-standard codes (Cloudflare 520–527, etc.) not included
  • Descriptions are summary-level — refer to RFC for exact spec

Real Ways People Use This

Debugging API Responses

Look up unfamiliar status codes your backend returns so you can fix the root cause instead of guessing.

SEO and Redirect Planning

Compare 301 and 302 behavior to avoid losing search rankings during a domain or URL migration.

Error Handling Design

Match server responses to the correct 4xx and 5xx codes so clients can react programmatically.

Onboarding New Developers

Give junior developers a fast, searchable reference while they learn how HTTP works in practice.

SEO Monitoring

Interpret crawler errors in Google Search Console by understanding what each status code means.

Important Notes
  • This page covers the most commonly used HTTP status codes, not every registered code in the IANA registry.
  • Some codes (like 418 I'm a teapot) are jokes in the spec and won't appear in real production traffic.
  • Browsers and API clients can handle the same code differently, so test redirects and errors in your actual environment.
Quick Checklist
  • 1Look up the exact code your server returned before assuming what went wrong.
  • 2Check whether the error is client-side (4xx) or server-side (5xx) to narrow your debugging.
  • 3Verify redirect codes (301 vs 302) when planning URL migrations.

Questions That Usually Come Up

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