What happens to my old website when a new one launches?

The loss is invisible, which is why it happens so often. A business launches a new site, everything looks better, and traffic falls over the following weeks without anybody connecting the two events. What actually happened is that thirty addresses that ranked for something now return errors, and the accumulated value at each one was discarded rather than transferred.

Export the list of existing addresses before anything changes, because reconstructing it afterward is considerably harder. Your analytics will show which pages received traffic, your search console will show which ones appeared in results, and a crawl of the existing site will list everything including pages you forgot about. Those three sources together produce a complete picture.

Map each old address to the closest equivalent on the new site rather than sending everything to the home page. A visitor following a link to a specific service wants that service, and the home page is technically a redirect and practically a dead end. Where nothing genuinely corresponds, a helpful error page offering the relevant alternatives is better than a redirect that misleads.

Use permanent redirects rather than temporary ones, because the distinction determines whether the accumulated value transfers. A temporary redirect tells search engines the old address is still the real one and will return, which is not what you mean when a site is being replaced.

Keep the addresses identical where you can, which removes the problem entirely for those pages. A rebuild does not require changing the address structure, and preserving it means the majority of your pages need no redirect at all. Businesses frequently restructure addresses during a rebuild for no reason beyond the new system's default, and that decision creates work and risk that was avoidable.

Test after launch rather than assuming, by visiting a sample of old addresses and confirming each lands where intended. Redirect chains, where one address points at another which points at a third, are a common outcome of doing this hastily and they dilute exactly what the redirect was meant to preserve.

Watch your search console for the following weeks, since that is where the failures appear. A rise in pages returning errors, or a fall in impressions for terms you previously appeared for, indicates something did not transfer. Both are visible within a fortnight and both are fixable at that point.

Then leave the redirects in place indefinitely rather than removing them after a period. They cost nothing, links on other sites persist for years, and somebody following a reference from three years ago should still arrive somewhere useful. Removing them later is a decision with no upside.

Keep a copy of the old site rather than deleting it once the new one launches, because questions arise about what a page said, what an old price was, or what a policy stated. A full export stored somewhere is a few megabytes and it answers those questions in seconds.

Tell anybody who links to you if the addresses did change, particularly partners, directories, and suppliers who list you. A redirect handles it technically and a direct link is always better, and most will update if asked once.

Update your business listings, your social profiles, and your email signature if any specific addresses changed, since those links are outside the redirect and will keep pointing wherever they were set.