About this status codes
Working with APIs and web services means constantly encountering HTTP status codes—but not everyone knows what each code means or how to fix the underlying issue. Our HTTP Status Codes Reference provides a complete, searchable guide to every standard HTTP status code, from the familiar 200 OK and 404 Not Found to less common codes like 418 I'm a Teapot. Whether you're debugging a REST API, building a web application, or troubleshooting server issues, this interactive reference eliminates confusion and accelerates problem-solving.
Unlike static documentation, this tool combines multiple features developers actually need: instant search by code number or description, automatic grouping by category (informational, success, redirection, client error, server error), and detailed explanations of when each status code occurs and why. Each HTTP response code entry includes the official definition, real-world causes for receiving that status, practical fixes and solutions, and working curl examples you can test immediately.
Every HTTP status code—from 100 Continue to 599 Network Connect Timeout Error—is documented with actionable troubleshooting steps. The grouped-by-category view helps you understand code families (1xx for information requests, 2xx for successful operations, 3xx for redirects, 4xx for client errors, 5xx for server errors) and common patterns. Filter results by status range or search natural language queries like "user not authorized" to find the code you need in seconds.
The integrated curl examples show exactly how API requests produce each status code, making this reference invaluable for API integration work, microservices debugging, and web development education. Search functionality works across code numbers, technical names, and plain English descriptions, so you can find answers however you naturally think about HTTP errors. All processing happens locally in your browser—your queries and debugging sessions remain completely private.
Whether you're a backend developer building REST APIs, a frontend engineer handling API responses, a QA engineer validating error handling, or a DevOps engineer monitoring service health, this HTTP status code lookup tool becomes an indispensable reference you'll return to regularly when facing any 4xx client error, 5xx server error, or 3xx redirect situation.
How to use this tool
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01
Search for a Status Code
Enter a code number (like 404), error name (like "Not Found"), or description (like "page missing") in the search box. Results appear instantly, showing all matching HTTP status codes with their official meanings and categories.
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02
Read the Full Code Details
Click or expand any status code to view complete information: the exact meaning, when servers return this code, common causes in real applications, and step-by-step fixes for different scenarios (API issues, browser requests, server problems).
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03
Reference the Curl Examples
Each status code entry includes working curl command examples that demonstrate how to trigger or test that specific HTTP response. Copy examples directly into your terminal to validate API behavior and understand status code handling in context.
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Explore by Category
Browse the grouped view to understand HTTP code families: 1xx (information), 2xx (success), 3xx (redirection), 4xx (client error), 5xx (server error). This systematic approach helps you learn patterns and predict how your API should respond in different situations.
Worked examples
404 Not Found - Debugging Missing Endpoints
500 Internal Server Error - Server-Side Problem Indicator
301 Moved Permanently - Redirect Handling
Limits and edge cases
- HTTP status code ranges group related responses: 1xx codes inform the client that the request is in progress, 2xx codes confirm the request succeeded, 3xx codes redirect to another location, 4xx codes indicate client request errors (bad syntax, authentication, authorization, missing resource), and 5xx codes indicate server errors. Understanding these ranges helps you troubleshoot API issues faster.
- Some HTTP status codes are rarely used in practice (like 418 I'm a Teapot, a humorous April Fools' reference, or 451 Unavailable For Legal Reasons). While this reference documents them completely, focus on common codes: 200 OK, 201 Created, 204 No Content, 301/302 Redirects, 400 Bad Request, 401 Unauthorized, 403 Forbidden, 404 Not Found, 500 Internal Server Error, and 503 Service Unavailable.
- When building APIs or debugging client code, match status codes to your response message and provide helpful details. A 400 Bad Request should explain what field failed validation; a 401 Unauthorized should describe the authentication method; a 403 Forbidden should clarify permission issues. Use this reference to select the precise HTTP status code that best describes each error scenario in your application.
Standards and references
Common questions
What's the difference between 404 Not Found and 410 Gone?
404 Not Found means the server can't find the requested resource right now, but it might exist later. 410 Gone means the resource permanently no longer exists and won't be available again. Use 410 when you've deleted content and want clients to stop requesting it; use 404 for temporary unavailability or incorrect URLs.
When should I return 400 vs 422 for validation errors?
400 Bad Request indicates the request syntax is invalid or malformed. 422 Unprocessable Entity means the request format is correct, but the semantic content fails validation (like missing required fields or invalid values). Use 400 for malformed JSON; use 422 when the JSON parses but fails business logic validation.
How do 301, 302, and 307 redirects differ?
301 Moved Permanently tells clients to update bookmarks permanently; search engines transfer SEO credit to the new URL. 302 Found is a temporary redirect; clients should keep using the original URL. 307 Temporary Redirect is like 302 but preserves the HTTP method (POST stays POST), while 302 might change POST to GET. Use 301 for permanent moves, 302 for temporary changes, and 307 when method preservation matters.