Website Redesign Without Losing SEO: A Migration Checklist Based on Google's Own Guidance

"Redesign" covers very different projects. A new colour palette on the same URLs is low risk. A new CMS that changes every URL path, merges pages and moves to a new domain in the same weekend is a site migration, and Google documents it as one. The first job is to write down which of the following your project includes, because each one triggers different checks.

Google's advice is to change one thing at a time where you can, for example moving the domain first and changing the layout later. If something goes wrong, you can tell which change caused it. It also suggests timing the move for a period of lower traffic if your business is seasonal.

The URL map is the single most important deliverable of a migration, and it should exist before the new templates are finished, not the night before launch. Google lists where to find old URLs: your sitemaps, server logs, analytics, the Links report in Search Console and the CMS itself. Include images, PDFs and other files that people link to, not only HTML pages.

Each row should end in one of three outcomes. Most old URLs redirect to the closest new page. Several old pages that were combined into one can all redirect to that consolidated page, which Google says is acceptable. Content you deliberately removed returns 404 or 410. What Google warns against is the shortcut of sending many old URLs to one irrelevant destination such as the new home page, which can confuse users and be treated as a soft 404.

Before you touch anything, export a baseline from Search Console: top pages and queries by clicks for the last few months. That list tells you which rows of the map deserve a manual check, and it is the only fair comparison after launch.

Google recommends server-side permanent redirects, 301 or 308, whenever technically possible. A permanent redirect tells Google's indexing pipeline that the target should become the canonical URL, and Google states plainly that 301 and other permanent redirects do not cause a loss in PageRank. Temporary redirects (302, 303, 307) do not send that canonical signal, so a 302 left in place after a CMS launch is a common reason the old URLs linger in results.

Client-side options are a fallback. Google treats an instant meta refresh as permanent, but it only recommends JavaScript redirects when server-side and meta refresh redirects are impossible, because a JavaScript redirect is only seen if rendering succeeds. On a Next.js, Shopify or WordPress site, that usually means defining redirects in the framework or platform configuration rather than in page code.

Avoid chains. If your site already had redirects from a previous redesign, update them to point straight at the new final URL. Googlebot can follow up to 10 hops, but Google advises redirecting directly to the destination, and otherwise keeping chains ideally to no more than 3 and fewer than 5, because each hop adds latency and not every browser supports long chains.

Many failed migrations are not ranking mysteries. They come from settings copied over from the staging site. Google's list of common mistakes starts with leftover noindex rules and robots.txt blocks from development, followed by redirects that point to URLs that do not exist and sitemaps that still list old URLs.

Bilingual sites need one extra pass. If you run English and French pages in Canada, or English and Japanese pages as this site does, every hreflang annotation must be updated to the new URLs. Google requires each language version to list itself and all other versions with fully qualified URLs, and it ignores the tags if two pages do not point to each other. A migration that updates the English templates first and the other language a week later breaks that pairing in the meantime.

Google recommends moving a small or medium site all at once and, for a large site, moving one section at a time. Expect Googlebot to crawl harder than usual right after launch, because it follows redirects from the old URLs; make sure the server or host can absorb that load.

Google's two documents give different minimums, which causes confusion. The site-move guide says to keep redirects for as long as possible, generally at least 1 year, so Google can transfer signals and recrawl links from other sites. The Change of Address help page says at least 180 days, longer if Google Search still sends traffic to the old URLs, and suggests keeping the old domain registered for at least a year. Our recommendation is simple: treat a year as the floor, and from a user's point of view keep important redirects indefinitely, as Google itself suggests.

Then give it time. For medium-sized sites, Google says it can take a few weeks or more before the new URLs gradually replace the old ones in results, longer for large sites, and that rankings can fluctuate in the meantime. Compare against your baseline weekly rather than reacting to a single day.