Free online HTTP status code reference - 1xx Information / 2xx Success / 3xx Redirect / 4xx Client Error / 5xx Server Error
301 is a permanent redirect — search engines transfer link equity to the new URL and remove the old URL from the index. 302 is a temporary redirect — search engines keep the old URL indexed and don't transfer equity. Use 301 for site migrations or URL changes, and 302 for temporary maintenance or A/B testing. Using 302 instead of 301 prevents SEO equity transfer.
1）Create custom 404 pages with navigation links and search; 2）Avoid soft 404s (returning 200 with error content); 3）Regularly check and fix 404 links; 4）Monitor 404 errors in Google Search Console; 5）Return 410 (Gone) instead of 404 for permanently removed pages to help search engines deindex faster.
500 Internal Server Error means the server encountered an unexpected error, usually a code bug or configuration issue. 503 Service Unavailable means the server temporarily can't handle requests (overloaded or under maintenance) but expects to recover. 503 should include a Retry-After header. Search engines are more tolerant of 503 and will retry later; they may reduce crawl frequency for 500 errors.
Yes. HTTP Status Code Reference is fully responsive and works on phones, tablets, and desktops. The interface adapts automatically to your screen size.
No. HTTP Status Code Reference is a web-based tool — just open it in your browser and start using it. No downloads, plugins, or extensions required.
Absolutely. All processing happens locally in your browser. No data is sent to any server, so there's zero risk of data leaks. Your information stays completely under your control.
No. HTTP Status Code Reference uses client-side processing — everything runs in your browser. Your data never leaves your device, and the tool works even without an internet connection.
Yes, HTTP Status Code Reference is completely free to use. No registration or login required — all features are available immediately.