HTTP Status Codes

What Are HTTP Status Codes?

HTTP status codes are three-digit numbers returned by web servers in response to client requests. They indicate whether a request was successful, failed, or requires further action. Status codes are essential for web development, debugging, and understanding server responses.

Status codes are grouped into five categories: 1xx (Informational) for provisional responses, 2xx (Success) for successful requests, 3xx (Redirection) for further action needed, 4xx (Client Error) for client-side issues, and 5xx (Server Error) for server-side problems.

How to Use This Tool

1. Search: Enter a status code number (e.g., “200”) or name (e.g., “Not Found”) in the search box to quickly find specific codes.
2. Filter: Use the category dropdown to view only codes from a specific range (1xx, 2xx, 3xx, 4xx, or 5xx).
3. Review Details: Each code card displays the status number, name, description, and when to use it with real-world scenarios.
4. Copy Code: Click the copy button on any code card to copy it to your clipboard for quick reference.
5. Identify Common Codes: Codes marked with a ★ star are the most commonly used in web development.

Common Use Cases

• Web Development: Understanding API responses and server behavior during development and debugging.
• API Integration: Handling different status codes when consuming third-party APIs and web services.
• Server Configuration: Setting up proper response codes for different URL patterns and error handling.
• Monitoring & Logging: Analyzing server logs to identify performance issues and user-facing problems.
• Client Development: Building proper error handling and retry logic in client applications based on status codes.
• SEO & Site Management: Understanding redirects (3xx) and error codes for search engine optimization.

Frequently Asked Questions

What’s the difference between 4xx and 5xx status codes?

4xx codes indicate a client error — the request was malformed, unauthorized, or invalid. The client should modify the request. 5xx codes indicate a server error — the server failed to fulfill a valid request. The server should be investigated or the request retried later.

What does status code 200 mean?

Status code 200 means OK — the request was successful and the server returned the requested data. It’s the most common response for successful HTTP requests.

Why do I see 301 vs 302 redirect codes?

301 is a permanent redirect — search engines and browsers cache it. Use for permanent URL changes. 302 is a temporary redirect — treated as temporary by browsers. Use for short-term redirects or A/B testing.

What should I do when I encounter a 500 error?

A 500 error is an internal server error — something went wrong on the server side. Try refreshing the page, checking if the service is up, and contacting the site administrator if the error persists. Check server logs for detailed error information.

Can I have custom HTTP status codes?

The HTTP/1.1 specification defines standard codes (100-599). While you could technically create custom codes, it’s not recommended as clients won’t understand them. Instead, use the closest standard code and include error details in the response body.

What are 1xx informational status codes used for?

1xx codes are interim responses indicating that the server received the request and is continuing processing. Common examples: 100 Continue (client should proceed with request body) and 101 Switching Protocols (for protocol upgrades like WebSocket).