301 redirects when changing your website: a plain-English guide

Redirects are the least glamorous part of a new website and the part that most decides whether it keeps its Google traffic. They are not difficult, but they are detailed, and they have to be planned before launch rather than patched afterwards. This guide explains what to ask for, how to check it was done, and the mistakes that quietly undo the work.

What is a 301 redirect, and why does it matter?

Every page on your site has an address, its URL. When a redesign changes that address, say from /our-kitchens.html to /kitchens/, anyone who arrives at the old one, from a Google result, a bookmark or a link on another website, finds nothing. A redirect is an instruction on the server that says "this page now lives here" and forwards the visitor instantly.

The number is a status code, a short message the server sends before the page. 301 means moved permanently. For Google, that matters: its documentation on redirects says a permanent redirect is a strong signal that the new address should be shown in results instead of the old one. That is how the standing an old page built up over years gets passed to its replacement.

Without redirects, a redesign throws away every link other sites ever gave you. With them, those links keep working for the new pages.

Which type of redirect should you use?

The common error is a 302 where a 301 was meant. Some tools and plugins default to temporary redirects, so check the type, not just that the page forwards.

Which old URLs need a redirect?

Any old URL that has value: visits, rankings, or links from other sites. In a typical redesign that includes:

• Every page whose address changes, including the ones that simply move into a new folder.
• Old blog posts and news items, which often hold more external links than the service pages.
• PDFs, brochures and price lists that people or other sites link to.
• Images that appear in Google Images or are embedded elsewhere, if the image addresses change.
• Pages merged into one, each redirected to the new combined page.
• Old redirects from earlier redesigns, which should be updated to point straight at the new final address.

Pages with no visits, no links and no equivalent on the new site do not need one. Google's site move guidance says those should return a 404 or 410 error, which is the honest answer for content that no longer exists.

How do you build the redirect map?

The redirect map is a two-column spreadsheet: old URL, new URL. Start from a complete list of old addresses, built from a crawl of the old site, its sitemap, and Google Search Console (Google's free reporting tool), which lists every page that received clicks or impressions in the past 16 months. Then fill in the right-hand column by hand for every page that matters. The website migration SEO checklist covers how to assemble the list.

Where many URLs follow the same pattern, a developer can write one rule instead of hundreds of rows, for example sending everything under /post/ to the same name under /journal/. Pattern rules are efficient, but they only work if the endings genuinely match, so spot-check a sample against real pages.

Where do the redirects actually live?

This is the point most owners are never told. A redirect is answered by whatever server your domain points at. When you leave a platform and point your domain at the new site, the old platform stops answering for your domain, and any redirects set up there stop mattering. The redirects must be built into the new site or its hosting.

• Custom sites on your own server: in the server configuration, such as an .htaccess file on Apache or the site configuration on Nginx.
• Modern hosting platforms: most offer a redirects file or settings panel; your developer will know which.
• WordPress: through the server, or a redirection plugin.
• Shopify: in the admin under URL redirects, one at a time or by CSV import. Shopify's documentation notes that a redirect only works when no live page exists at the old address. Shopify migration SEO covers the details.
• Wix and Squarespace: each has its own redirect settings, which matter when moving to them or changing URLs within them, not after you leave. See moving off Wix, Squarespace or WordPress.

If the domain name itself is changing, the old domain must stay registered and pointed at a server that answers every old URL with a 301 to its new equivalent.

What are the mistakes that cost rankings?

• Sending everything to the homepage. It is quick, and Google warns it can be treated as a soft 404, meaning the old page is regarded as gone and its value is not passed on.
• Chains. Old page to older redirect to new page. Google's guidance is to avoid them; each old URL should reach its final address in one step.
• Loops. Two addresses redirecting to each other, which shows the visitor an error.
• Redirecting to a page that does not exist. A typo in the new address turns a redirect into a 404.
• Missing variants. The http and https versions, www and non-www, and versions with and without a trailing slash should all resolve to one final address.
• Temporary instead of permanent. A 302 tells Google to keep the old address in results.
• Removing redirects after a few months because the site "has settled". Other sites keep linking to the old addresses for years.

How long should you keep redirects, and how do you test them?

Google's site move guidance says to keep redirects "as long as possible, generally at least 1 year". Its Change of Address tool, used when a domain name changes, forwards signals for 180 days and asks that redirects stay for at least that long. Since a redirect costs almost nothing to maintain, the practical answer is to keep them permanently.

To test them:

1. Paste a sample of old addresses into a browser and check each lands on the right page.
2. Run the full old URL list through a redirect checker or a crawler in list mode, and confirm each returns a single 301 to the expected address.
3. Use Search Console's URL Inspection tool on a few old URLs after launch to see what Google finds.
4. Watch the Pages report in Search Console for "Not found (404)" errors over the following weeks, and add redirects for any that matter.

If rankings have already fallen and redirects are the suspect, lost rankings after a redesign explains how to rebuild the old URL list after the fact. For where redirects sit in the whole project, read how to redesign your website without losing Google rankings.