A redesign can change the way a site looks without changing its URLs. When URLs also change, it becomes a migration: every useful old page needs a relevant new destination, and search engines need to discover that relationship. Treat the URL plan as part of the build, not an afterthought on launch day.
Inventory the site before drawing new pages
Export current URLs from the sitemap, CMS and analytics. Add pages with search clicks, backlinks, leads or sales that may be absent from a current menu. Record each page's topic and purpose. Mark pages that will stay, move, merge or disappear. Keep a copy of current titles, metadata and body content so useful answers are not lost during design.
Make a one-to-one URL map where the content still exists
For each changing URL, choose the closest relevant new page. Do not send an old service article to the homepage merely because its replacement is unfinished. If two pages are genuinely consolidated into one stronger page, both can point to it. If there is no replacement, a real 404 or 410 is clearer than an unrelated redirect. Google's site-move documentation recommends permanent server-side redirects and warns against redirect chains.
Check the new site before launch
Check that important pages render as HTML, work on mobile, and are not blocked by robots.txt or a leftover noindex tag. Every indexable page should name its own canonical URL. Update navigation, contextual links and XML sitemap entries to the final URLs. If the site has language versions, check that hreflang links point to real reciprocal pages.
Launch with a crawl, not a visual sign-off alone
Crawl the old URL list and confirm each response reaches the intended destination. Crawl the new sitemap and check status, title, canonical, main heading and internal links. Test forms and purchase paths. Record the launch date and keep the old redirects in place long enough for users and crawlers to encounter them.
Watch the right signals afterwards
In Search Console, compare indexing, errors and impressions by page group. Expect some movement during recrawling; investigate patterns such as many important pages becoming excluded, old URLs pointing to 404s or a sudden loss of enquiries. Do not judge the migration from a single day of rankings.
This checklist is the minimum handover for a redesign. The Siren Web Studio web design service includes page structure and measurement planning before the new site is built.