Codes HTTP : La référence complète
Tous les codes HTTP essentiels
Every time a browser requests a page, the server responds with an HTTP status code. These three-digit numbers tell browsers and search engines whether the request succeeded, redirected, or failed.
Status Code Categories
1xx: Informational. 2xx: Success. 3xx: Redirection. 4xx: Client error. 5xx: Server error.
Most Important Codes
200 OK
Success — page loaded correctly. This is what you want for all important pages. Check with our HTTP Status Code Checker.
301 Moved Permanently
Page permanently moved. Transfers ~90-99% of link equity. Use for URL changes and domain migrations. Generate with our Htaccess Redirect Generator.
302 Found (Temporary)
Temporary redirect. Does not pass full link equity. Use only for genuinely temporary moves.
404 Not Found
Page does not exist. A few are normal, but many indicate broken links. Fix by redirecting to relevant pages.
410 Gone
Intentionally removed. Google de-indexes 410 pages faster than 404.
500 Internal Server Error
Generic server error. Usually code bugs or misconfiguration. Needs server-side investigation.
503 Service Unavailable
Temporarily overloaded or in maintenance. Google retries later. Use Retry-After header during planned downtime.
SEO Impact
301 vs 302: Always use 301 for permanent moves — 302 does not pass full link equity.
404 chains: Too many broken links signal poor maintenance to Google.
5xx errors: Frequent errors reduce crawl rate and hurt rankings.
Redirect chains: Keep to max 2 hops. Check with our Redirect Checker.
Frequently Asked Questions
What is the best status code for SEO?
200 for live pages, 301 for permanently moved pages.
How do I find 404 errors?
Google Search Console Pages report, or our HTTP Status Code Checker.
Should I fix all 404 errors?
Focus on pages with backlinks or traffic. 301 redirect to the most relevant existing page.
Check your pages with our HTTP Status Code Checker and trace redirects with Redirect Checker.