HTTP Status Codes Reference

Complete list of HTTP status codes with detailed explanations, usage scenarios, and client-side code examples. 100% free and interactive.

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Quick Tip

Standard HTTP status codes are maintained by the IANA. Use these codes correctly to improve SEO and developer experience.

17 Status Codes Found

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How to Use

The HTTP Status Codes Reference is a specialized developer guide for understanding the standard response codes sent by web servers.

How to use this tool

Search by Code: Type a specific number (like 404) into the search bar to find its meaning instantly.
Browse Categories: Use the sidebar to filter by group: 1xx (Informational), 2xx (Success), 3xx (Redirection), 4xx (Client Error), or 5xx (Server Error).
Expand for Details: Click on any status code card to see a deep explanation, common use cases, and code examples for implementation.
External Docs: Each entry includes direct links to official MDN documentation and fun visual aids like HTTP Cats.

About This Tool

The Language of the Web

HTTP response status codes indicate whether a specific HTTP request has been successfully completed. They are grouped into five classes based on their first digit, ranging from informational responses to severe server failures.

Proper use of status codes is critical for modern web development. It ensures that browsers handle redirects correctly, that search engines can index your content effectively, and that your client-side applications can provide meaningful feedback to users when things go wrong.

Why Use This Tool

Why a Reference Tool?

While many developers remember the common codes like 200 or 404, the HTTP specification contains dozens of specialized codes (like 429 for rate limiting or 304 for caching) that are essential for high-performance applications. This tool provides an interactive, easy-to-navigate reference that includes implementation snippets, saving you time spent digging through long specification documents.

FAQ

What are the main categories of HTTP status codes?

Status codes are grouped into five categories: 1xx (Informational — request received, processing), 2xx (Success — request accepted), 3xx (Redirection — further action needed), 4xx (Client Error — bad request), and 5xx (Server Error — the server failed to process the request).

What is the difference between 301 and 302?

301 (Moved Permanently) indicates the resource has permanently moved — search engines will transfer SEO value to the new URL. 302 (Found) indicates a temporary move — the original URL retains its SEO value. Use 301 for permanent URL changes and 302 for temporary redirects.

What does a 403 error mean vs a 401?

401 (Unauthorized) means the request lacks valid authentication credentials — the client must authenticate. 403 (Forbidden) means the server understands the request but refuses to authorize it — authentication won't help because the resource is forbidden for that user.

When should you use the 204 No Content status code?

204 indicates success but with no response body. It is commonly used for successful DELETE operations, CORS preflight responses, and when an action completed but there is no data to return to the client.