Replacing an existing site is a different job to building a new one: the risk is losing what already works. This checklist covers redirects, SEO preservation, content parity and a safe cutover.

When you replace a site, the danger is not what you build, it is what you lose: rankings, links, and pages people already rely on. Everything in the new-build checklist still applies. These are the extra steps that protect the value already in the ground.

Map and redirect every URL

Crawl the existing site and export the full list of live URLs.
Map each old URL to its new equivalent; decide deliberately on anything with no match.
Implement 301 (permanent) redirects, not 302s, and avoid redirect chains.
Keep the redirect map in source control; you will need it again.

Preserve SEO equity

Carry over or improve title tags and meta descriptions for ranking pages.
Update internal links to point at the new URLs, not through redirects.
Re-point canonical tags and check structured data survived the move.
Identify your top-traffic and top-converting pages and protect them first.

Content parity

Confirm every page of value migrated; no orphaned or dropped content.
Check media, downloads and embeds came across and still resolve.
Decide what to retire on purpose, and redirect those URLs somewhere useful.

Analytics and Search Console continuity

Keep the same GA4 property so historical data stays comparable.
Add a launch annotation so future-you knows why the graphs moved.
If the domain changes, use the Search Console change-of-address tool.
Submit the new sitemap and watch coverage and crawl errors daily for a fortnight.

Off-site and legacy

Update the links you control: Google Business Profile, social profiles, directories.
Ask key partners and high-value backlinks to point at the new URLs.
Keep the old environment and a backup until the new site is proven stable.

Cutover and watch

Lower DNS TTL ahead of time; cut over in a low-traffic window.
Spot-check a sample of redirects in the browser immediately after launch.
Monitor rankings, traffic and conversions against the pre-launch baseline, and keep the redirect map ready for anything you missed.