Should you really care about the difference between 301 and 302 redirects?

Why does Google still make this distinction in 2025?

The theory goes that a 301 redirects signals to Google that the old URL has been permanently replaced: the engine then transfers ranking signals (PageRank, age, backlinks) to the new page. A 302, intended to be temporary, should maintain signals on the original URL — since it is expected to return.

However, in practice, many sites use 302s by default or by mistake, never returning to the original URL. Google had to adapt: if the 302 remains in place for weeks or months, the algorithm treats it de facto as a 301. Mueller confirms this without specifying an exact timeframe — typical of Google, which refuses to give numerical thresholds.

What is the technical difference between a 301 and a 302?

A 301 Moved Permanently tells the browser and search engines that the resource has permanently changed its address. The HTTP 301 status is cached by browsers, which speeds up future visits but complicates error corrections.

A 302 Found (or 307 Temporary Redirect in HTTP/2) indicates a temporary move. Crawlers are supposed to return to check the original URL regularly. In theory, this preserves the indexing of the old page — but if the 302 persists, Google eventually ends up indexing the target, not the source.

When is a 302 actually used?

Legitimate cases for 302 redirects are rare: temporary A/B tests, planned maintenance with a return expected to the original URL, dynamically localized redirects (which change based on user IP), or seasonal pages that come back each year.

The problem? Many CMSs and frameworks generate 302s by default during migrations or slug changes. The result: "temporary" redirects that last for years, causing a slow dilution of signals until Google switches to 301 mode.

• 301: immediate and complete transfer of ranking signals to the new URL
• 302: signals retained on the old URL as long as the redirect remains “fresh”
• Persistent 302: Google eventually treats as a 301, but with an undocumented delay
• Default choice in most CMS: often 302, which requires increased vigilance during migrations
• Browser cache: a 301 is aggressively cached, a 302 much less

Is this statement consistent with real-world observations?

Yes, but with one major caveat: Mueller does not specify the time threshold after which Google switches a 302 to a 301. Real-world tests show this can occur between 3 weeks and 3 months depending on the site's crawl frequency. On a high crawl budget site, the switch is quicker — Google quickly detects that a 'temporary' one is not.

The second observation: the transmission of PageRank via a persistent 302 is less clear-cut than with a direct 301. Some signals seem to get lost in the confusion as Google hesitates between the two URLs. This is invisible in the Search Console but manifests in rankings during the transition period. [To be verified]: no official data on the exact loss rate during this phase.

What are the flaws in this directive?

Mueller says nothing about chains of redirects: what happens if a 302 points to a 301, then another 301? Does Google follow the entire chain or cut off at a certain level? Tests show that beyond 3 successive redirects, the transfer of PageRank becomes random.

Another blind spot: JavaScript redirects and meta refresh. Officially, Google handles them 'like normal redirects,' but their processing is much slower than an actual HTTP status. If you use a 'temporary' JS redirect, expect it to be ignored for weeks before Googlebot actually detects it.

In what cases does this rule not apply?

Geo-targeted redirects are a borderline case: a 302 that changes target based on the user’s country will never be treated as a 301, because Google crawls from various IPs. The same applies to user-agent based redirects (mobile vs desktop) — obsolete since mobile-first indexing, but still present on some old sites.

Finally, redirects on expired domains: buying an old domain and redirecting all its URLs in 301 to your site no longer transfers much after several years. Google detects these patterns and cancels the transfer of PageRank. A 302 would be even more suspicious.

What should you actually do during a migration?

Use exclusively 301s for any URL that will never return. No 302s 'just in case': if you're unsure, the redirect is permanent. Site migrations, slug changes, category merges — all require a 301.

Test your redirects with an HTTP tool (curl, Screaming Frog, or simply the browser's network inspector) to verify the returned code. Many WordPress plugins generate 302s by default — modify the config or change plugins. On Shopify, manual redirects are always 301s, but automatic ones (deleted product) can be 302s.

What critical mistakes should be avoided?

Never let a 302 'linger' for more than a few days if the original URL should not return. Each week of uncertainty is diluted PageRank and fluctuating rankings. Google does not switch instantly — in the meantime, you lose positions on competitive queries.

Avoid redirect chains: URL A → 302 → URL B → 301 → URL C. Google follows, but slowly, and the transfer of signals is partial. Always redirect directly from A to C. Regular audits with Screaming Frog to detect these hidden chains, especially after several successive migrations.

How to audit existing redirects on a mature site?

Run a complete crawl with Screaming Frog in 'List' mode: import all your indexed URLs (via sitemap or Search Console), and check the response codes. Filter for '302' — each line must have justification. If a 302 has been in place for over 2 months, switch it to 301 immediately.

Also use server logs to identify redirects frequently crawled by Googlebot: if a 302 is visited 50 times a day for 6 months, it should be a 301. Logs also reveal hidden chains that Screaming Frog might miss (JS redirects, meta refresh).

• Ensure all post-migration redirects are 301s, not default 302s
• Audit redirect chains and eliminate unnecessary intermediaries
• Check redirects via curl or the network inspector: the CMS may lie in its interface
• Monitor Googlebot logs to spot 302s that persist abnormally
• Document every legitimate 302 (A/B test, seasonal) to avoid it being 'corrected' by mistake
• Test behavior after browser caching: a 301 may block a quick correction if misconfigured