What is a 301 redirect
A 301 redirect is a permanent redirect from an old URL to a new one. It tells both the visitor and Google that the page has moved permanently to a new address.
When a page moves or a site is rebuilt, URLs change. Without a redirect the visitor would hit an error page and the old page's SEO value would be lost.
A 301 redirect smoothly sends the visitor to the new page and passes most of the old page's SEO value along.
Why a 301 redirect matters
When updating a site, the 301 redirect is what preserves SEO rankings. Without it a new site would lose the old site's accumulated value and start from zero in search.
How a redirect works
When a browser requests the old address, the server answers with status code 301 and the new address. The browser opens the new page at once, and the visitor notices nothing except a changed URL. Google's crawler gets the same answer, gradually replaces the old address with the new one in its index and carries over the value of links the old page had earned.
The number 301 means moved permanently. Code 302 means a temporary redirect: Google keeps the old address in the index because it expects the page to come back.
When you need a 301 redirect
A redirect is needed whenever a working address changes or disappears.
- A new website or redesign that changes the URL structure.
- A domain change, for example from oldname.ee to newname.ee.
- Moving from http to https and settling on one of the www and non-www variants.
- Merging two similar pages into one, or sending a discontinued product to its category.
Example: a new site and old addresses
An accounting firm's old site used addresses like /index.php?page=services. The new site uses /services/accounting. The old address has been in Google for years, and business directories and partner sites link to it.
Before launch, a table is prepared: every old address on the left, the matching new one on the right. Each old page is pointed to the new page closest in content. The old sitemap and the page list in Search Console are the sources for that table.
Common mistakes and how to check
The most common mistake is sending every old address to the home page. Google often treats such a redirect as if the page did not exist, and the value is not passed on. The second is a chain, where A redirects to B and B to C: each extra hop slows loading. The third is removing redirects too early. Google advises keeping them for at least a year.
To check, open a few old addresses in a browser after launch and see where you end up. The Pages report in Search Console lists Not found (404) and Page with redirect, which reveals addresses that were missed.
Frequently asked questions
What is the difference between a 301 and a 302 redirect?
A 301 is permanent: Google replaces the old address with the new one. A 302 is temporary: the old address stays in the index. If a page has moved for good, use a 301. A 302 suits a short-lived campaign page, for example.
Does a 301 redirect lose SEO value?
A correctly set redirect to a page with the same content passes the value on. Rankings may fluctuate for a while after a move as Google processes the new addresses. Losses happen when the redirect points to an unrelated page or is missing altogether.
How long should redirects stay in place?
At least a year, ideally permanently. Other websites, bookmarks and printed material may still point to the old addresses, and without a redirect those visitors reach an error page.