What happens to my old web addresses?

Every page on your current site has an address, like yourbusiness.com/water-heaters. Google remembers those addresses, other websites link to them, and some customers have them bookmarked. When you switch, every one of them still has to go somewhere.

Every old address gets one of two answers

A page, at the same address. If your new site has a page at that exact address, it simply shows the new page.

A forward to the closest page. Otherwise, the old address forwards visitors and Google to the closest page we have. That's a page on the same topic if there is one, then a page with the same purpose, then the page above it. Your homepage is the last resort, because Google treats lots of pages forwarding to a homepage as pages that were deleted.

Your blog posts and legal pages are different: they keep their exact addresses and their exact words. More on that.

What a "permanent forward" means

The technical name is a permanent redirect. When a visitor or Google asks for an old address, the site answers "this page has moved here for good," and sends them on. Google carries over what it knew about the old page to the new one.

Old addresses that end in .html, .php or .aspx, which older website builders often use, are handled the same way.

Once a forward is set, it stays

An old address that forwards keeps forwarding, through every future update of your site. It never goes back to "page not found." If the page it points to is ever taken off your site, the forward moves to the nearest live page instead.

An address that was never on your old site, and isn't on your new one, gets an honest "page not found." That's what Google expects.