SEO for a website relaunch: how to not lose your rankings

A site relaunch (new design, new CMS, new URL structure) is routinely planned entirely as a design and development project, with SEO considered afterward if at all. It's also one of the few events reliably capable of losing years of accumulated rankings within days if handled carelessly.

The single highest-risk step is URL structure changes: every old URL that doesn't map to a clear new equivalent needs a 301 redirect, mapped individually, not blanket-redirected to the homepage: a mistake I still see on relaunched sites months later, quietly leaking authority that took years to build.

The pre-launch checklist that actually matters: a full crawl and export of every existing indexed URL before the old site goes offline, a redirect map built against that export rather than guessed at, and confirmation that the new site's robots.txt and meta robots tags aren't accidentally set to noindex from staging.

None of this is exotic technical work. It's tedious, unglamorous list-making, which is exactly why it gets skipped under launch-deadline pressure, and exactly why it's the difference between a relaunch that holds its rankings and one that spends the next two quarters recovering them.