Definition

301 redirect (permanent): A server-side instruction that a URL has moved permanently to a new location.

308 redirect: The HTTP/2+ equivalent of a permanent redirect; functionally similar for SEO.

Canonicalization: Google's process for selecting the representative URL when duplicates/variants exist.

Signal consolidation: Transfer of accumulated link equity and other signals from old → new URL.

Evidence (Plain-English Summary)

• Google treats permanent redirects (301/308) as strong canonical signals and will try to consolidate signals to the target URL.
• Since 2016, PageRank isn't lost across 30x redirects; however, canonical selection still depends on multiple signals (internal links, canonicals, sitemaps, content match).
• Keeping redirects in place for a long time (≥ 1 year) helps ensure users, bots, and external links migrate fully.
• Excessive redirect chains, irrelevant hops, or mass redirects to non-equivalent pages can trigger soft-404 handling and limit consolidation.

Best Practices

Use 301/308 for permanent changes.

Reserve 302/307 for truly temporary moves.

Map 1:1 and keep intent equivalent.

Old "blue widget guide" → new "blue widget guide," not to a generic category or homepage.

Update all reinforcing signals.

• Internal links point to the new URL.
• Canonical tags, sitemaps, hreflang, Open Graph/Twitter tags use the new URL.
• Navigation and breadcrumbs updated.

Minimize chains and hops.

Aim for one hop (old → new). If you have legacy chains, collapse them to point directly to the final destination.

Keep redirects live ≥ 12 months (longer if possible).

Allows Google and external sites to catch up; many links are slow to change.

Prefer server-side redirects (HTTP 3xx).

Avoid JS or meta-refresh unless you have no server-side access.

Maintain parity.

New URL should load, be indexable (no accidental noindex), and return 200 with substantially the same or improved content.

Common Pitfalls

• Redirecting to irrelevant pages (e.g., many old articles → homepage) → can be treated like soft-404s.
• Leaving internal links pointing at old URLs → mixed signals; slower canonicalization.
• Long redirect chains/loops → crawl inefficiency, potential loss of consolidation.
• Short-lived redirects (removed within weeks) → equity doesn't fully transfer; users/bookmarks break.
• Forgetting protocol/host/casing rules (http→https, www/non-www, trailing slash) → duplicate paths and conflicts.

Quick Decision Guide

Is the move permanent?

• Yes → Use 301/308.
• No/unsure → Use 302/307 (temporary) and avoid content/intent changes.

Does the target match the source intent?

• Yes → Proceed (strong consolidation expected).
• No → Find a closer match or keep the original.

Are all signals consistent with the new URL?

• Yes → Faster canonicalization.
• No → Update internal links, canonicals, sitemaps, hreflang.

Implementation Checklist

• Server-side 301/308 from every old URL → correct new URL (one hop).
• Content/intent parity between old and new pages.
• Internal links updated site-wide to the new URLs.
• Canonical tags on new pages self-reference; old pages 301 only (no indexable duplicates).
• XML sitemaps list only new URLs; remove or de-prioritize old ones.
• hreflang references updated across all language/region variants.
• Redirects retained ≥ 12 months (longer if high-value).
• Monitor in GSC (URL Inspection, Indexing report) and analytics for traffic/crawl anomalies.

TL;DR for the Hub

Are 301s a ranking factor? No (directly). Do they affect rankings? Yes (indirectly)—by consolidating signals so the new canonical can inherit what the old URL earned. Use permanent, one-hop redirects to equivalent destinations, align all supporting signals, and keep them in place long enough to stick.