- Use a 301 or 308 redirect to a closely equivalent page whenever a URL moves permanently.
- Redirect relevance matters more than redirect type: mass-pointing old URLs to the homepage is treated like a soft 404.
- Collapse redirect chains to a single hop and update internal links so you stop depending on redirects.
- Keep redirects live for at least a year, and longer for URLs with strong backlinks.
Few technical SEO topics cause more anxiety than redirects. Owners worry that every redirect leaks authority, while developers assume that any redirect will do. The truth sits in between. Redirects are a signal that tells search engines one URL has been replaced by another, and how well that signal is understood depends on how cleanly you implement it. This guide explains what actually happens to ranking signals and how to act on it.
What a redirect really communicates
A redirect is an instruction: the content you requested now lives somewhere else. Search engines use that instruction to decide which URL to keep in the index and where to consolidate signals such as links, relevance and history. Consolidation is the key idea. Google does not hand over a fixed percentage of value; it uses redirects as one of several hints to pick the canonical version and merge what it knows about the old and new pages.
That means a redirect to a truly equivalent page tends to carry signals across well, while a redirect to something unrelated may simply be ignored.
Choosing the right redirect type
- 301 (moved permanently): the default for domain moves, URL restructures, HTTPS and merged pages.
- 308 (permanent redirect): a permanent equivalent that preserves the request method; treated like a 301 for search purposes.
- 302 and 307 (temporary): for genuinely short-term moves such as an A/B test or maintenance page. Search engines may keep the original URL indexed.
- Meta refresh and JavaScript redirects: they can work, but they are slower to process and less reliable. Use server-side redirects whenever possible.
In practice, a long-running 302 is often eventually treated as permanent, but do not rely on that. If the move is permanent, say so with the right status code.
Relevance beats technique
The most common mistake is a lazy mapping. When a retired product page, a deleted blog post and a dead category all point to the homepage, search engines frequently classify those redirects as soft 404s. The result is no signal transfer, and users land somewhere irrelevant and leave.
Map each old URL to the closest equivalent by intent. If no equivalent exists, a proper 404 or 410 is the honest answer, and it is better than a misleading redirect. For a discontinued product, a good fallback is the parent category or a successor product, but only if it truly serves the same need.
Chains, loops and hidden delays
Every extra hop adds latency and a chance for something to break. Google will follow a limited number of hops, but long chains slow crawling and dilute clarity. Chains usually build up over time: HTTP to HTTPS, then non-www to www, then an old slug to a new slug.
- Crawl your site and export every URL returning a 3xx status.
- Flatten chains so each old URL points straight to the final destination.
- Fix loops immediately; they return errors to users and crawlers.
- Update internal links, canonicals, sitemaps and hreflang to reference final URLs, not redirecting ones.
Internal links are especially important. Redirects are meant to catch outside traffic and old backlinks, not to carry your own navigation.
A migration checklist that protects rankings
Whether you are changing domains, replatforming or restructuring, the same discipline applies.
- Inventory first: list all indexed URLs, top landing pages and URLs with external backlinks before anything changes.
- Build a one-to-one map: prioritise pages with traffic and links, and have a human review the matches.
- Test on staging: check status codes, final destinations and parameters in bulk.
- Launch and verify: submit updated sitemaps, watch Search Console for crawl errors and coverage shifts, and compare landing-page traffic against your baseline.
- Keep redirects long term: maintain them for at least a year, and indefinitely for URLs with valuable backlinks.
Expect some short-term volatility even with a flawless setup, because search engines need time to reprocess. A clean migration usually stabilises; a sloppy one keeps bleeding.
When not to use a redirect
Redirects are not a fix for everything. For duplicate or near-duplicate pages that must stay live, such as filtered or tracking-parameter versions, a canonical tag is the better tool. For content you are temporarily removing, a 503 or a normal page may be more appropriate. And for pages with no replacement, resist the urge to redirect just to avoid seeing 404s in a report; a clean 404 is perfectly healthy.
Conclusion
Redirects preserve ranking signals when they are permanent, relevant, direct and well maintained. They waste them when they are generic, chained or temporary by accident. If you are planning a migration or suspect old redirects are holding your site back, the technical SEO team at Growth Asteroid can audit your redirect map and protect the authority you have built.
Frequently asked questions
Does a 301 redirect pass all ranking signals?
Not as a guaranteed fixed amount. A 301 to an equivalent page lets search engines consolidate signals onto the new URL, but results depend on relevance and clean implementation.
Is a 302 redirect bad for SEO?
Only when used for a permanent move. For genuinely temporary changes it is correct, but permanent moves should use a 301 or 308 to make the intent clear.
How long should I keep redirects in place?
Keep them at least a year, and indefinitely for URLs that still receive backlinks or steady traffic, since removing them can cause those signals and visitors to be lost.