Migrating a legacy site without losing your search rankings

Most traffic lost in a replatform is lost in the first fortnight, and almost all of it is avoidable. The content survives; the addresses do not.

Inventory before you build

Export every URL the old site serves — from the CMS, from the sitemap, from server logs, and from Search Console. Logs matter most: they show what is actually being requested, including pages the CMS no longer lists but Google still indexes.

Map old to new, explicitly

Produce a spreadsheet with one row per old URL and its new destination. Anything that cannot be mapped gets a deliberate decision: redirect to the closest parent, or let it 410. Never bulk-redirect everything to the home page — search engines treat that as a soft 404 and drop the page anyway.

Preserve the signals, not just the pages

• Titles and meta descriptions carry over per page, not regenerated wholesale.
• Canonical URLs point at the new addresses and agree with the sitemap.
• Structured data survives the move.
• Redirects are 301, single-hop. Chains leak authority and slow crawling.

Verify before and after launch

Crawl the staging site and compare against the inventory. After go-live, crawl the live site, submit the new sitemap, and watch Search Console's coverage report daily for a fortnight. Spikes in 404s are the early warning that a mapping rule missed a pattern.

A migration that keeps its URLs is invisible to users and to search engines. That is the goal.