HTTP Status Codes: Complete Reference Guide | Free Tool

A 404 Not Found means the server cannot find the requested resource. The most common HTTP error seen by users.

A 301 Moved Permanently tells browsers and search engines that a page has permanently moved to a new URL. Search engines transfer link equity.

A 500 Internal Server Error means the server encountered an unexpected condition. It is a generic server-side error.

A Yes.

A Yes, absolutely. Our HTTP status code reference provides detailed descriptions and use cases for all 3xx redirect codes, like 301 Moved Permanently and 302 Found. Understanding their nuances is crucial for SEO, as incorrect redirects can impact link equity, indexing, and user experience. Use the tool to compare codes and ensure you're implementing the most SEO-friendly redirect strategy for your website.

A The 401 Unauthorized status code means a request lacks valid authentication credentials. The server requires the client to log in. In contrast, 403 Forbidden means the server understands the request but refuses to authorize it, even with valid credentials, due to insufficient permissions. Our HTTP Status Code Reference tool helps you quickly compare these subtle differences, providing detailed descriptions and use cases to accurately diagnose access control and authentication issues.

A Absolutely. When you're working with APIs, understanding specific status codes is key to debugging. For instance, a 400 Bad Request often signals a problem with the data you sent. Or maybe a 503 Service Unavailable means the API is temporarily overloaded. You can use the search and filter functions here to pinpoint the exact code and its typical causes, saving you development time.

A A 429 status code means you've hit a rate limit. Servers use this to prevent abuse or overload. You'll see it when your app sends too many requests in a short window. Check the Retry-After header in the response — it tells you exactly how many seconds to wait. Our tool lists this detail under the 4xx section. Back off, wait the specified time, then retry. For APIs, implement exponential backoff to handle this gracefully.

A Most people assume a 200 OK means everything is perfect. Not quite. A 200 can mask problems like slow page loads or broken internal logic. For example, an API might return 200 with an error message in the JSON body. Our tool helps you look beyond the code — each entry explains common pitfalls. Always check the response body alongside the status code.