33 status codes documented with examples

Complete HTTP Status Codes Reference

Look up any HTTP response code. Understand what it means, why it happens, and how to fix it.

🔍

Status Code Categories

HTTP responses are grouped into five categories. Click any category to explore its codes.

Quick Reference

Click any status code for a detailed explanation, troubleshooting guide, and real HTTP examples.

Monitor Your Website 24/7

Don't wait for users to report errors. Get instant alerts when your site returns 5xx errors, goes down, or SSL certificates expire.

Uptime monitoring Status code checks SSL monitoring Instant alerts
Start Free Monitoring

Frequently Asked Questions

Quick answers to common HTTP status code questions.

What are HTTP status codes? +
HTTP status codes are 3-digit numbers returned by a web server in response to a browser's request. They indicate whether the request was successful (2xx), redirected (3xx), caused a client error (4xx), or triggered a server error (5xx). For example, 200 means OK, 404 means Not Found, and 500 means Internal Server Error.
What is the difference between 301 and 302 redirects? +
A 301 redirect is permanent - search engines transfer link equity to the new URL and update their index. A 302 redirect is temporary - search engines keep the original URL indexed. Use 301 for permanent URL changes like site migrations or HTTPS upgrades, and 302 for temporary situations like A/B testing or maintenance pages.
How do I fix a 500 Internal Server Error? +
To fix a 500 error: 1) Check your server error logs for specific details. 2) Review recent code changes or deployments. 3) Verify file permissions are correct. 4) Check for syntax errors in configuration files like .htaccess. 5) Ensure your server has sufficient memory and disk space. 6) Test database connectivity.
What causes a 502 Bad Gateway error? +
A 502 Bad Gateway error occurs when a server acting as a gateway or proxy receives an invalid response from an upstream server. Common causes include: the upstream server crashing or being overloaded, firewall rules blocking communication, PHP-FPM process timeouts, or network issues between servers. These errors are often temporary.
How can I monitor my website for HTTP errors? +
Use a website monitoring service like HTTP Tiger to continuously check your site's HTTP status. Monitoring services send requests to your URLs at regular intervals and alert you when errors occur, helping you fix issues before your users notice them.