HTTP Status Code Reference
Search sixteen common HTTP status codes and learn what each response means.
Complete guide to HTTP Status Code Reference
Tool Overview
The HTTP Status Code Reference provides quick explanations of the numeric response codes returned by web servers and applications. These codes indicate whether a request succeeded, was redirected, failed because of a client issue, or encountered a server-side problem.
HTTP codes are grouped into categories: 1xx informational responses, 2xx successful responses, 3xx redirections, 4xx client errors, and 5xx server errors. Understanding them is fundamental for web development, SEO, API debugging, server administration, and website maintenance.
Why Use an HTTP Status Reference?
When a browser, crawler, API client, or monitoring tool requests a URL, the status code provides an immediate summary of the outcome. 200 OK generally means the request succeeded. 301 Moved Permanently indicates a permanent redirect. 404 Not Found means the requested resource was not found, while 500 Internal Server Error points to a server-side failure.
SEO professionals use status codes when auditing broken links, redirect chains, deleted pages, soft errors, and migration behavior. Developers use them to design API responses and troubleshoot applications. Correct status codes also help clients and automated systems understand what action to take next.
Use Cases
- Look up the meaning of an unfamiliar HTTP code.
- Diagnose broken URLs during an SEO audit.
- Choose an appropriate response code for an API.
- Understand redirects during a site migration.
- Troubleshoot server and application errors.
- Train developers or content teams on common web responses.
Frequently asked questions
What does 200 mean?
200 OK indicates that the request was successfully processed and the server returned the requested response.
What is the difference between 301 and 302?
A 301 traditionally signals a permanent redirect, while a 302 signals a temporary redirect. Search engines and clients can treat them differently depending on context.
What is a 404 error?
404 Not Found means the server cannot find a resource matching the requested URL.
What does 403 mean?
403 Forbidden indicates that the server understood the request but refuses to authorize access to the resource.
What is the difference between 500 and 503?
500 Internal Server Error is a general server failure. 503 Service Unavailable usually indicates temporary unavailability, such as maintenance or overload, and can optionally include retry information.
Can the wrong status code affect SEO?
Yes. Incorrect redirects, error pages returning 200, or unavailable pages returning inappropriate responses can confuse crawlers and make indexing and diagnostics less reliable.