How to Look Up HTTP Status Codes

Search and understand all HTTP status codes from 1xx to 5xx. Get clear explanations, common use cases, and troubleshooting tips for every response code.

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Step-by-Step Guide

1

Search for a status code

Type the HTTP status code number (like 404 or 502) or a keyword (like "not found" or "timeout") into the search bar. The tool instantly filters the complete list to show matching codes. You can also browse by category: 1xx Informational, 2xx Success, 3xx Redirection, 4xx Client Error, and 5xx Server Error.

2

Read the detailed explanation

Each status code entry includes the official name, a plain-English description of what it means, when servers return it, and the HTTP specification reference. This goes beyond just the code name — it explains the practical meaning so you can diagnose issues quickly.

3

Understand common causes and fixes

For error codes (4xx and 5xx), the tool lists typical causes and recommended fixes. For example, a 429 Too Many Requests means you are hitting rate limits and should implement retry logic with exponential backoff. A 503 Service Unavailable usually indicates temporary server overload.

4

Use the code in your application

Each entry shows how the status code is typically used in REST APIs and web applications. Learn which codes to return from your own API endpoints — return 201 Created after successful resource creation, 204 No Content for successful deletions, and 422 Unprocessable Entity for validation failures.

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Frequently Asked Questions

What is the difference between 401 and 403?
401 Unauthorized means the request lacks valid authentication credentials — the client needs to log in or provide an API key. 403 Forbidden means the client is authenticated but does not have permission to access the requested resource. In short: 401 is "who are you?" and 403 is "you cannot access this."
What does a 502 Bad Gateway error mean?
A 502 Bad Gateway means a server acting as a reverse proxy or gateway received an invalid response from the upstream server it was forwarding the request to. Common causes include the upstream server being down, network issues between servers, or the upstream server returning a malformed response. It is almost always a server-side infrastructure issue, not a client problem.
Which HTTP status codes should my REST API return?
Use 200 OK for successful GET requests, 201 Created for successful POST that creates a resource, 204 No Content for successful DELETE, 400 Bad Request for malformed requests, 404 Not Found for missing resources, 409 Conflict for duplicate resources, and 500 Internal Server Error for unexpected server failures. Be specific — generic 200 for everything makes debugging harder.
Related Reference

HTTP Status Codes Cheat Sheet

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