What Is a 301 Redirect? (And When to Use One)

A 301 redirect is a server response that permanently sends both visitors and search engines from an old URL to a new one. Use it whenever a page moves, a domain changes, or two pages merge. Google treats a 301 as a permanent move, transfers ranking signals — including the backlinks pointing at the old URL — and eventually replaces the old URL in its index.

301 vs 302 vs 307: the difference that matters

All three send a browser somewhere else. What separates them is what they tell a search engine about permanence.

Code	Meaning	Search engine behaviour	Use it for
301	Moved permanently	Consolidates signals onto the destination; old URL drops out of the index	Moved pages, merged pages, domain and protocol changes
302	Found (temporary)	Keeps the original URL indexed; treats the move as short-lived	A/B tests, brief maintenance, genuine short-term diversions
307	Temporary redirect (HTTP/1.1)	Same intent as a 302, preserves the request method	Temporary moves where POST data must survive
308	Permanent redirect	Same intent as a 301, preserves the request method	Permanent moves on APIs and forms

The costly mistake is using a 302 for a permanent move. Google will often eventually work out the truth, but in the meantime you've told it the old URL is still the real one, which delays consolidation and muddles which version ranks. If the move is permanent, say so.

When to use a 301

You changed a URL. New slug, new folder, new category structure.
You moved domain. Rebrand, or merging two properties into one.
You moved from HTTP to HTTPS, or www to non-www. Every variant should redirect to a single chosen version.
You merged two pages. Two thin articles on the same topic become one strong one; the loser 301s to the winner. This is also the standard fix for keyword cannibalisation.
You deleted a page that had backlinks. Redirect it to the closest genuine equivalent rather than letting those links die into a 404.
You have trailing-slash or uppercase duplicates. Pick one form and redirect the rest.

When not to use one

The old page still has a purpose. Redirecting a page that people still want is a worse experience than keeping it.
There's no relevant destination. A 301 to an unrelated page — or worse, everything to the homepage — is treated by Google as a soft 404 and passes essentially nothing. If the content is genuinely gone with no equivalent, a clean 404 or 410 is the honest answer.
The content is only temporarily unavailable. Use a 302, or a 503 with a retry header for maintenance.
You're trying to consolidate duplicates that both need to stay live. That's what a canonical tag is for — it points search engines at the preferred version while leaving both URLs accessible to users.

Do 301 redirects pass link equity?

Yes. Google's guidance on redirects treats a permanent redirect as a signal to consolidate the old URL's ranking signals onto the new one, and Google has stated since 2016 that PageRank is not lost through 3xx redirects. In practice, that means the backlinks pointing at your old URL keep working after the move — provided the redirect is to a genuinely relevant page.

Two things still cost you:

Time. Consolidation isn't instant. Google has to recrawl the old URL, see the redirect, and process the move. On a large site that can take weeks, which is why traffic dips after a migration are normal and usually recover.

Relevance. The signals transfer because Google accepts the destination as the successor to the original. Redirect a well-linked article about backlink pricing to your homepage and there's no successor relationship to honour — the redirect is treated as a soft 404 and the equity evaporates. Map old URLs to their closest real equivalents, one by one.

Redirect chains and loops

A chain is A → B → C. It works for users, but every extra hop adds latency, spends crawl budget, and gives more opportunity for a link in the chain to break. Chains accumulate quietly over years of site changes — each redesign redirecting to the previous redesign's URLs.

Fix them by pointing every old URL directly at the current live destination. A → C, B → C. Audit for chains after any migration, and again a year later.

A loop — A → B → A — is fatal: the browser gives up and the page is unreachable to both users and crawlers. Loops usually come from two rules that each look correct in isolation, like a trailing-slash rule and a lowercase rule fighting each other.

Where 301s and backlinks intersect

This is the part that matters most for link building, and the part most often skipped.

Every URL change breaks the links pointing at it. Backlinks are earned once and pointed at a specific URL. Change that URL without a redirect and every one of those links now aims at a 404 — the link still exists on the other site, but it delivers nothing. That's the most avoidable way to lose links you already paid for in time or effort.

Your own 404s are a link-reclamation opportunity. Crawl your site for broken inbound links, find the ones with real referring domains, and 301 each to the closest live page. It's the fastest link win available, because you control both ends and need no one's permission — a point covered in how to find backlinks to your website.

Redirected links are still real links. A backlink that resolves through a 301 to your current page counts. You don't need to email anyone to update the URL, though asking is still worth doing for high-value placements, since a direct link removes a hop and can't break later. It's also worth telling any active exchange partner when you move a page — on Backlinkster, where each swap is verified live by code, a moved URL is exactly the kind of change that's better handled with a redirect than a broken check.

How to set one up

The mechanism depends on your stack, but the concept is identical everywhere:

Next.js — a redirects() block in next.config.js with permanent: true.
Apache — Redirect 301 /old-path /new-path in .htaccess, or a RewriteRule with the [R=301,L] flag.
Nginx — return 301 /new-path; inside a location block.
WordPress — a redirect plugin, or your SEO plugin's built-in redirect manager. WordPress also creates some automatically when you change a slug.
Cloudflare / Netlify / Vercel — rules or a _redirects file at the edge, which is the fastest option because the request never reaches your origin server.

Always test with a tool that shows the actual status code and hop count, not just whether the browser lands in the right place — a chain and a clean 301 look identical to a user.

Frequently asked questions

How long should I keep a 301 redirect in place? Indefinitely, if you can. Google reprocesses the move within weeks, but backlinks and bookmarks pointing at the old URL can persist for years, and removing the redirect turns all of them into 404s. Treat redirects as permanent infrastructure.

Does a 301 redirect hurt SEO? A correct one to a relevant destination doesn't. What hurts is redirecting to irrelevant pages, building long chains, or using a 302 for a permanent move. A short-term ranking wobble after a migration is normal and typically recovers.

Can I redirect an entire domain to a new one? Yes, and you should map URL-to-URL rather than sending everything to the new homepage. Also use the Change of Address tool in Google Search Console to signal the move explicitly.

What's the difference between a 301 redirect and a canonical tag? A 301 makes the old URL inaccessible and forwards everyone to the new one. A canonical leaves both URLs working but tells search engines which to index. Use a 301 when the old page should be gone; use a canonical when both need to stay live.

Do 301 redirects work for links from other websites? Yes. An external link pointing at a redirected URL passes its value to the destination, so you don't lose backlinks when you move a page — as long as the redirect exists and stays in place.

The bottom line

A 301 is the difference between moving a page and losing it. Used correctly — permanent code, relevant destination, no chains, left in place forever — it carries your rankings and your backlinks to the new URL with minimal loss. Used carelessly, by redirecting everything to the homepage or skipping redirects during a redesign, it's one of the quickest ways to throw away links that took months to earn.