--- title: 301 Moved Permanently description: What HTTP 301 means, when to use it over 302/308, how it affects SEO, and how to debug redirect chains. canonical: https://watchfor.io/docs/reference/http-status-codes/301 --- # 301 Moved Permanently What HTTP 301 means, when to use it over 302/308, how it affects SEO, and how to debug redirect chains. **301 Moved Permanently** tells the client the resource has a new permanent URL (in the `Location` header) and that everyone — browsers, caches, search engines — should update their references. Browsers cache 301s aggressively, and search engines transfer the old URL's ranking signals to the new one. ## When it's the right choice - Domain migrations (`old-brand.com` → `new-brand.com`) - Enforcing one canonical form: `http://` → `https://`, apex → `www` (or the reverse), trailing-slash normalisation - Retired URL structures after a site redesign If the move is temporary, or you're redirecting a POST and need the method preserved, use [302](/docs/reference/http-status-codes/302) or 307/308 instead. 308 is the method-preserving equivalent of 301. ## Common problems - **Redirect chains** — `http://example.com` → `https://example.com` → `https://www.example.com` → the page. Every hop adds a round trip and dilutes crawl budget; collapse chains to a single hop where possible. - **Redirect loops** — A 301s to B, B 301s back to A. Browsers give up with `ERR_TOO_MANY_REDIRECTS`; the usual cause is conflicting rules between the CDN, the web server and the application. - **Cached forever** — because browsers cache 301s (often with no expiry), pointing one at the wrong target hurts for a long time. Test with a 302 first, then switch to 301 once verified. - **Losing the query string** — misconfigured rules drop `?utm_...` or search parameters during the hop; check your rewrite flags. ## Debugging The free [HTTP header checker](/http-header-checker) shows the full redirect chain hop by hop — each status, each `Location`, and where it finally lands. For continuous coverage, an [HTTP monitor](/docs/monitors/web) can either follow redirects and assert on the final page, or assert that a specific URL keeps returning exactly 301 to the right target — useful insurance after a migration, where one bad deploy can silently drop your redirect rules. --- Canonical page: https://watchfor.io/docs/reference/http-status-codes/301 · All docs: https://watchfor.io/docs · Site guide: https://watchfor.io/llms.txt