URLs, redirects and migrations

First, do not change the URL

An address that has existed for years has accumulated things you cannot see: links from other sites, bookmarks, references in email, an established position in an index. Changing it discards some of that even when everything is done correctly, and everything is rarely done correctly.

The rule for a clinic is therefore: change a URL only when the benefit is structural and permanent. A URL that is ugly but working is not a reason. A URL that is wrong because it contains a year, a campaign name or a brand you may no longer use is a reason, as is a restructure that consolidates pages that should never have been separate.

When a change is justified

• Consolidating several near-duplicate pages into one, which usually improves all of them.
• Moving from a structure with no hierarchy to the plan from Module 09, Information architecture: the site plan, once, at a point where the site is small enough to map completely.
• Removing a brand name from a URL where Module 05, The rules that constrain everything you publish says it should not be there.
• Changing platform or domain, where the change is forced rather than chosen.

Notice that three of the four are one-off events. If your clinic is changing URLs more than once every few years, the problem is the decision-making rather than the URLs.

The URL map

Before anything else, produce a spreadsheet with one row per existing URL. Get the list from three places and merge them, because no single source is complete: your sitemap, the pages report in Search Console, and a crawl of the site.

Against each row, write the destination. Every row must have one. Where a page genuinely has no equivalent, the destination is the closest parent page, and where even that does not exist, the row is a deliberate decision to let the page go, which should be rare and should be recorded.

How a redirect should behave

Permanent, which is a 301 status, so that the engine understands the move is not temporary. Direct, meaning the old address points at the final destination rather than at another redirect. And specific, meaning it points at the closest equivalent page.

Redirecting everything to the homepage is the single most damaging shortcut available. It tells the engine that none of the old pages had an equivalent, which is almost never true, and it produces an appalling experience for anybody following an old link. Google's guidance on site moves with URL changes is the reference and it is worth reading in full before, not during, a migration.

Four mistakes

The fourth is not a joke. Migrations produce faults, the faults are visible within hours in Search Console and in the server log, and the cost of a fault is proportional to how long it sits unattended.

Verifying afterwards

Immediately: request each of your twenty most important old URLs and confirm each returns a permanent redirect to the right place, in one hop. This is a ten-minute job and it catches most faults.

Over the following month: watch the page indexing report for a rise in not-found errors, watch the performance report for pages that stop appearing, and check that the new URLs are being indexed. Google's guidance on debugging traffic drops is the right document to have open if something goes wrong, because it separates the causes systematically rather than by guesswork.

Expect a dip. A migration done correctly still moves things about while the engine re-learns the site. What you are watching for is a dip that does not recover within a couple of months.

Keep the redirects in place permanently. Removing them after a year, on the grounds that nothing uses them, breaks every external link at once, and external links are the one asset a clinic cannot rebuild by itself.