Complete HTTP status code list with meanings, common scenarios, suggested solutions, and SEO highlights
HTTP status codes are three-digit numbers returned by a web server in response to a client's request. They are a fundamental part of the HTTP protocol, serving as a standardized communication method between servers and clients. Every time you visit a website, submit a form, or interact with a web API, the server responds with one of these codes. Understanding them is essential for web developers, system administrators, SEO specialists, and anyone working with internet technologies. Status codes are organized into five categories: 1xx (informational), 2xx (success), 3xx (redirection), 4xx (client errors), and 5xx (server errors). Each code carries specific meaning about what happened with the request, making them invaluable for debugging web issues, optimizing site performance, and improving search engine rankings. Our comprehensive HTTP status codes reference tool provides detailed descriptions, common scenarios, suggested fixes, and SEO relevance for every major status code.
Browse the complete list of HTTP status codes organized by category. Use the filter buttons at the top to narrow down codes by their class — informational (1xx), success (2xx), redirection (3xx), client errors (4xx), or server errors (5xx). You can also click the SEO filter to highlight codes that directly impact search engine optimization, such as 301 redirects, 404 pages, and 500 errors. This categorization helps you quickly locate the specific status code you are investigating without scrolling through the entire list.
Use the search box to find a specific status code by its number, name, or description. For example, typing '404' will instantly show you the Not Found error along with its explanation. Each code entry includes a detailed description of what the status means, the most common scenarios where it appears in real-world web traffic, and practical suggestions for how to fix or handle the situation. This makes the tool invaluable for debugging production issues, troubleshooting API integrations, or resolving SEO audit findings.
Review the suggested solutions and SEO notes for each status code. For client errors like 400, 403, or 404, the tool provides actionable recommendations on how to resolve them on your server. For server errors like 500, 502, or 503, you will find diagnostic steps to identify the root cause. The SEO highlights help you understand which status codes affect your site's crawlability and ranking, enabling you to prioritize fixes that have the greatest impact on your search visibility and user experience.
What is the difference between a 301 and a 302 redirect? A 301 redirect is a permanent redirect that tells search engines the page has moved permanently, and they should transfer all link equity to the new URL. A 302 redirect is temporary, indicating the page will return to its original location. Using 301 for permanent moves preserves your SEO rankings, while 302 is appropriate for temporary maintenance or A/B testing. Mixing them up can cause significant indexing issues and loss of search traffic over time.
Why does my website return a 500 Internal Server Error? A 500 error is a generic server-side error indicating something went wrong on the server while processing the request. Common causes include misconfigured .htaccess files, PHP memory limits exceeded, database connection failures, plugin conflicts in CMS platforms like WordPress, or corrupted server scripts. To diagnose, check your server error logs for detailed messages, disable recently installed plugins or themes, verify database connectivity, and ensure your server has sufficient resources to handle the request load.
How do HTTP status codes affect SEO? Status codes play a critical role in how search engines crawl and index your website. Codes like 200 (OK) and 301 (permanent redirect) are SEO-friendly, while 404 (Not Found) and 500 (Server Error) signal problems. Too many 404s waste crawl budget and frustrate users. Soft 404s (pages returning 200 but showing error content) are particularly harmful because they mislead both users and search engines. Regularly monitoring your status codes helps maintain a healthy site architecture and optimal search performance.