Redirect
Redirect is an HTTP response that tells a browser (or a search engine crawler) to go to a different URL than the one requested. Technically, it’s a response in the 3xx status-code family, with a Location header naming the destination. Redirects are how the web handles URL changes without breaking existing links - and how SEO teams hand over authority from old pages to new ones during site migrations.
The main redirect types
301 - Moved Permanently. Tells clients and search engines the URL has moved for good. Cached aggressively. Passes link equity to the destination. The default choice for any permanent URL change.
302 - Found (Temporary Redirect). Signals a short-term redirect. Search engines historically treat 302s as not passing equity, though modern Google behaviour is more forgiving than the old rule. Use for genuinely temporary situations.
307 - Temporary Redirect. Similar to 302, but preserves the HTTP method. A POST request redirected via 307 stays a POST; via 302 it may silently become a GET. Matters for forms and APIs.
308 - Permanent Redirect. Like 301, but preserves the HTTP method. Newer code; used where method preservation matters.
For SEO-facing URL changes on static pages, 301 is almost always the right answer. The others matter in more specific technical contexts.
Why redirects matter for SEO
Three reasons:
Link equity preservation. When a URL changes, external backlinks to the old URL become broken. A 301 redirect from old to new passes most of the accumulated authority forward. Skipping the redirect means losing the backlink equity entirely.
Crawl efficiency. Search engine crawlers have finite budget per site. Redirect chains and loops waste it. A clean redirect map - one hop per old URL, all pointing at a live destination - preserves crawl budget.
User experience. A broken link from another site to yours lands the visitor on a 404 instead of the content they wanted. A redirect sends them to the right place and saves the referral.
Where redirects go wrong
Four common problems:
Redirect chains. A → B → C → D. Each hop costs crawl budget and load time. Google still follows up to ten hops, but the impact on both SEO and user experience compounds. Flatten every chain to a single hop where possible.
Redirect loops. A → B → A. Caused almost always by misconfigured HTTPS-enforcement or trailing-slash rules. Break the site entirely; critical to catch before deploying.
Redirecting everything to the homepage. After a site migration, teams sometimes redirect all old pages to the homepage in bulk. Google treats this as a soft-404 - the destination doesn’t match the intent of the incoming link. Always redirect to the closest topically-matched live page, or let the URL return a proper 404.
Mixing 301 and 302 incorrectly. Using 302 for permanent moves weakens SEO consolidation. Using 301 for genuinely temporary moves means reversing the redirect later will be slow to take effect due to cache persistence.
A site-migration worked example
A B2B SaaS renaming its brand changed all URLs from old.com/features/x to new.com/platform/x. The team built a redirect map of 847 URLs, mapped each old URL to the closest new topical match, and implemented 301s at the web server level. One week post-launch, organic traffic dropped 12% - normal expected volatility during a migration. Six weeks in, traffic was within 3% of pre-migration levels. Twelve weeks in, organic traffic had exceeded pre-migration levels; the rebrand had resolved older messaging inconsistencies. The redirect discipline was the difference between a temporary dip and permanent loss.
Redirect and canonical URL - related, not identical
Both tools help search engines handle duplicate URL situations, but they mean different things:
A redirect tells the browser and crawler “this URL no longer serves content; go fetch a different one.” The original URL ceases to resolve.
A canonical tag tells the crawler “this URL resolves, but treat URL X as the authoritative version for indexing.” The original URL still serves content.
Use redirects when the old URL is genuinely gone. Use canonicals when the URL still needs to exist (for tracking parameters, pagination, session IDs) but shouldn’t be indexed independently.
We built Penfriend to produce content whose URLs stay stable for years - which makes redirect management rare rather than constant. URL changes happen only when content changes meaningfully, and redirect chains don’t accumulate because URL churn doesn’t.
Related terms
- Canonical URL - the other main SEO tool for de-duplicating URL variants
- On-Page Optimization - redirects are part of technical on-page hygiene
- Keyword Research - drives the mapping logic for which URL replaces which
- Header Tags (H1, H2, H3) - topical relevance signal used when choosing redirect destinations
- Meta Description - should be reviewed on the new URL when the old one is redirected