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HTTP Status Code Reference

A comprehensive guide to HTTP status codes with detailed explanations and triage tips.

Updated

What is the HTTP Status Code Reference?

HTTP response status codes are essential indicators that tell you whether a specific HTTP request has been successfully completed. Whether you are a developer debugging an API, a sysadmin monitoring server health, or an SEO specialist troubleshooting crawl errors, understanding these codes is crucial for maintaining a healthy web presence.

Our HTTP Status Code Reference tool provides an interactive, searchable database of all standard and common non-standard status codes. Each entry includes:

  • Official Definitions: Based on the latest RFC specifications.
  • Triage Guides: Practical advice on how to fix common errors.
  • Quick Links: Direct access to MDN and RFC documentation for deep dives.

Stay ahead of web issues by quickly identifying the meaning behind every 1xx, 2xx, 3xx, 4xx, and 5xx response.

How it works

This tool is designed for speed and clarity. Here is how you can use it effectively:

  1. Search: Use the search bar to type in a specific numeric code (e.g., 403) or a keyword (e.g., Forbidden). The list will filter instantly as you type.
  2. Filter by Category: Use the category buttons or the dropdown menu to narrow down your search to specific classes of codes:
  • 1xx (Informational): Request received, continuing process.
  • 2xx (Success): The action was successfully received, understood, and accepted.
  • 3xx (Redirection): Further action must be taken to complete the request.
  • 4xx (Client Error): The request contains bad syntax or cannot be fulfilled.
  • 5xx (Server Error): The server failed to fulfill an apparently valid request.
  1. Detailed View: Click on any status code in the list to open its detailed profile. This view provides the full description, a triage guide for troubleshooting, and official documentation links.
  2. Copy and Share: Use the copy button to quickly grab the status code and name for your documentation or bug reports.

Examples

Lookup 404 Not Found

Find out why a resource is missing and how to fix it.

404
 
Not Found: The server cannot find the requested resource.

Check 200 OK

Understand the standard response for successful requests.

200
 
OK: The request succeeded.

Frequently asked questions

What are HTTP status codes?

HTTP status codes are three-digit integers returned by a web server in response to a client's request. They indicate whether the request was successful, if there was an error, or if further action is needed.

What is the difference between 4xx and 5xx errors?

4xx status codes are Client Errors, meaning the issue is likely with the request itself (e.g., a typo in the URL or missing authentication). 5xx status codes are Server Errors, indicating that the server encountered an issue and could not fulfill a valid request.

What does a 404 Not Found error mean?

A 404 error means the server could not find the requested resource. This usually happens when a page has been moved or deleted, or when the user types the URL incorrectly.

Why is the 418 I'm a teapot code used?

The 418 status code was created as an April Fools' joke in RFC 2324. While it is not a standard functional code, many servers and frameworks support it as an "Easter egg" to indicate they refuse to brew coffee in a teapot.

How can I fix a 500 Internal Server Error?

Since a 500 error is a generic server-side crash, the best way to fix it is to check the server's error logs. Common causes include syntax errors in code, permission issues, or exhausted server resources.

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