301 and 302 Redirects: When and How
7 min
A 301 redirect (permanent) transfers almost all SEO authority to the new URL and tells Google to update its index. A 302 (temporary) preserves the source URL in the index and does not transfer authority. Use 301s quasi-systematically in SEO, except for precise technical needs to preserve the original URL.
Redirects are surgical tools. Used correctly, they preserve your authority during a migration or restructuring. Poorly chosen, they can leave your authority suspended for months on dead URLs.
301 permanent vs 302 temporary: what Google does with each
A 301 redirect signals to Google that the page has permanently changed address. Google updates its index to replace the old URL with the new one and transfers accumulated PageRank to the destination. The process takes a few weeks.
A 302 redirect indicates a temporary move. Google keeps the source URL in its index and does not transfer PageRank to the destination. This is the intended behavior in rare cases, such as short-term maintenance or an A/B test.
- Domain migration: 301 mandatory on all URLs.
- URL structure redesign: 301 toward new URLs.
- Temporary page maintenance: 302 toward a replacement page.
- A/B test on a destination URL: 302 to preserve the index on the original.
- HTTP to HTTPS redirect: permanent 301.
Classic errors that cause authority loss
Redirect chains (A redirects to B which redirects to C) are the most frequent error after one or more successive migrations. Each link in the chain slightly attenuates the authority transfer and slows down crawling. Always point directly to the final destination.
Redirect loops (A redirects to B which redirects to A) make the page inaccessible and generate an ERR_TOO_MANY_REDIRECTS error in the browser. Googlebot abandons after a few hops.
Redirect chains of 3 levels or more can reduce authority transfer by 10 to 25%, according to SEO specialist estimates based on 2024-2026 field tests.
Sector studies 2025-2026 on SEO migrations and authority
Setting up and monitoring redirects
On Apache, redirects are configured in the .htaccess file. On Nginx, in the server{} blocks of the configuration file. Most CMSs (WordPress, Shopify) offer plugins or native modules for managing redirects without server access.
After a migration, check redirects in Search Console (coverage errors), with Screaming Frog (list mode to validate all source URLs), and monitor organic traffic page by page for 4 to 6 weeks.
Redirects and backlinks: what to do
When you redirect a URL that has powerful backlinks, the 301 transfers most of the authority to the destination. Ideally, contact sites pointing to the old URL to update their links — direct links are always more powerful than a redirect.
Keep 301 redirects active indefinitely, or at minimum for 12 to 24 months. Removing a redirect too early reactivates the old URL as a 404, breaking backlinks and erasing the transmitted authority.
FAQ
How long does Google take to follow a 301 redirect?
Google generally follows a 301 and updates its index within 2 to 8 weeks. On very frequently crawled pages, it can be faster. On pages with few links, it can take several months.
Does a 301 redirect transfer 100% of PageRank?
In theory no: Google indicates a small share may be lost in the redirect. In practice, on a direct 301 (no chain), the transfer is near-total. Field studies confirm a marginal loss, generally less than 5%.
Can you redirect a page to one with completely different content?
Technically yes, but Google may ignore the authority transfer if the two pages have no thematic relevance in common. Redirects should not be used to artificially merge unrelated pages.