Every business that has had a website for a few years owns something it has never thought about: a set of addresses other people depend on. A customer bookmarked the page with your service hours. A supplier linked to you from their partners page in 2019. Google has been sending people to your about page for years. A local news story still points at a page you forgot existed.
You built those addresses. Everyone else built on top of them.
That's how I approach every redesign and every platform move. The old addresses stopped being only yours a long time ago, and a new website doesn't get to break them just because it's new.
A launch is the riskiest day for a URL
Nobody wakes up and decides to break a hundred links. It happens because a new site is designed around the new site. The pages get better names, the structure gets cleaner, the menu makes more sense. All good things. And every old address that doesn't make the trip turns into a dead end on launch day.
The people who hit those dead ends don't file a complaint. They hit "page not found" and leave. Some of them were ready to call.
The old platform has been covering for you
Here's the part that surprises owners. Many older sites, WordPress especially, have a habit of covering for missing pages. Visit an address that no longer exists, and WordPress often guesses a page with a similar name and sends you there. It's been quietly patching holes for years, and nobody on the inside ever saw the holes.
A site that's been redesigned once or twice can have old addresses still "working" that way, with no redirect anyone ever wrote. The guesses leave when the platform does. That's not an argument for staying on an old platform. WordPress has had a long run, and keeping it alive is a lot of effort to protect a habit. It's an argument for knowing what the old site has been doing for you before you leave it.
What I ask for before anything moves
A list. Every address the old site has ever answered to, from its sitemap, from Google's own records and from archived copies of the site, each with one new home on the new site. One permanent redirect per address, in one step. Then a few weeks of watching for anything the list missed.
What the old addresses tell you
The list does a second job, and it's the one I find most useful as a strategist. The addresses other people linked to, bookmarked and searched for are a map of what your customers valued. The page a supplier chose to link. The article Google kept sending people to. The service page someone saved.
Before a new site decides what to keep, cut or rewrite, that map is worth reading. It's years of customers voting with their clicks, and it's free.
AI assistants remember them too
More people now ask an AI assistant instead of typing a search, and those tools learned about your business partly from the addresses that have been out in the world for years. When an assistant points someone to a page, it's often one of those.
An old address with a new home keeps that path open. One that breaks is a page the assistant can't use. The same list that protects your customers protects how you're described in AI answers.
It's the work nobody notices
None of this is glamorous. It's the kind of work nobody notices when it's done right, which is exactly the point. The goal of a new website is that everything gets better and nothing you already earned gets lost.
The list is yours
One more thing I'd ask for: keep the list. It belongs to the business, not to whoever built the site. The next redesign, the next platform, the next agency will need it, and it's far easier to hand over a list than to rebuild one from archives years later.
If you're in the middle of a move and want the practical version (what to check, and what to ask whoever is building it), I wrote that up on nimblefish.net. And if you'd rather talk it through, I'd be glad to.
