A migration costs you rankings for three reasons, and three only: addresses changed without a permanent redirect, content disappeared along the way, or the new site stayed blocked from indexing. Everything else — the design, the technology, the host — has no direct effect on rankings. All three causes are entirely avoidable, provided the inventory is done before anyone touches the site.
Here is the procedure we follow, from the first audit to the week-four check. It applies to a redesign on the same domain and to a domain change alike.
Before touching anything: three inventories
1. The complete list of current URLs. All of them, including the pages you had forgotten. Cross three sources: your XML sitemap, the pages export from Search Console, and a full crawl of the site. The crossing is what matters — the sitemap almost never holds everything, and Search Console only lists what Google has seen.
2. A snapshot of your rankings and working pages. Export twelve months from Search Console: queries, pages, clicks, impressions, average position. That file is your comparison point after the switch, and it will not exist if you do not take it beforehand. Without it you can never demonstrate that anything was lost, or where.
3. The list of pages with inbound links. These are the most valuable: an inbound link points at one precise address, and if that address errors out after the migration the value of the link is gone. A page with no traffic but three good inbound links deserves a carefully chosen redirect, however useless it looks to you now.
The inventory happens first. After the switch it is too late: the old addresses are gone.
The redirect map, one line per address
A two-column table: old address, new address. Every old address must point to the closest match in content, with a permanent redirect — a 301, not a 302. The difference is not cosmetic: a temporary redirect tells Google to keep the old address, and you stay stranded between the two indefinitely.
The most common mistake is redirecting everything to the home page. It is fast, and it is exactly what not to do: Google treats a mass redirect to the home page as a disguised error page, and the value of the old pages evaporates. If an old page has no equivalent, send it to the nearest category or service page.
Three details that cost real money when forgotten: redirects must resolve in a single hop, with no intermediate chain; they must be kept for at least a year and ideally forever; and they must cover both the trailing-slash and non-slash variants, as well as the www and non-www versions.
Switch-over day
Six checks, in order, the same day. Redirects genuinely return 301 — test twenty at random, not one. The indexing block is lifted. The robots file forbids nothing essential. The new XML sitemap is generated and submitted to Search Console. The security certificate is valid on every address. And each page’s canonical tag points at itself, not at the old address and not at the home page.
That last check is the one skipped most often, and on its own it is enough to keep a page out of the index. A misdirected canonical throws no visible error: the page works, it looks right, and Google simply declines to rank it because it declares itself a duplicate of something else.
Pick your moment: a Tuesday morning, never a Friday afternoon or the eve of your busy season. And keep a full backup of the old site, files and database, for at least three months.
The four weeks after
Week 1: watch the page error report in Search Console and fix every not-found address within 48 hours. Week 2: compare indexed page counts against the old figure. Week 3: pull out your rankings export and compare query by query. Week 4: check that internal links no longer point at old addresses — a redirect is not an excuse to leave stale links inside your content.
What is normal: a 10 to 20% dip in organic traffic for two to six weeks, then a return to the previous level, often above it if the new site is faster and better structured. What is not normal: a drop of more than 40%, or a decline that persists beyond eight weeks. In both cases the cause is nearly always one of the three at the top — look for missing redirects first, then blocked indexing.
Changing domain is a different job
A redesign on the same domain recovers in a few weeks. A domain change asks for more patience: Google has to transfer one domain’s history to another, and that takes two to six months. The procedure adds two steps: declare the change of address in Search Console, and keep the old domain alive with its redirects for at least a year. Never let the old domain lapse — you would lose in one day everything the redirects were preserving.
If the rebuild decision is not settled yet, the criteria are in when to redesign your website. And if you want to know what condition the current site is in before moving it, a proper assessment covers exactly these points: see what a free SEO audit should contain.
After the switch the real work is upkeep: backups, updates, error monitoring. That is what our maintenance plan, from $120 a month, covers — Canadian hosting included. And if you would rather have someone read your redirect map before you go live than after, book the call — that is the hour that saves three months.