A website migration feels risky because you have heard the horror stories: a company relaunches a redesigned site and its search traffic falls off a cliff the same week. That does happen. What is less understood is that it is almost never the new platform's fault. It is the fault of a handful of boring details that got dropped in the move.
- Migrations lose rankings when signals get dropped, not because Google dislikes new platforms.
- The big risks are missing redirects, lost metadata, and changed URLs that return errors.
- Map every old URL to its new home with a 301 redirect, in one hop.
- Record a baseline before launch so you can prove nothing slipped, and catch it fast if it did.
Where the risk actually comes from
A migration does not lose rankings because search engines dislike your new stack. It loses rankings when the signals a page spent years earning get dropped in the move. Those signals live in specific, unglamorous places: the URL, the redirects, the page metadata, the internal links, and the content itself. Break any of them carelessly and the traffic follows.
The usual culprits behind a traffic drop are consistent and, importantly, all preventable:
- Old URLs that return an error instead of redirecting to their new location.
- Redirects that point to the wrong page, or chain through several hops before landing.
- Title tags, meta descriptions, and structured data lost in the rebuild.
- Internal links left pointing at the old, now-dead URLs.
- Pages that quietly get left behind and never make it to the new site at all.
Map every old URL to its new home
This is the single most important step, and the one most often rushed. Before launch, you list every URL that currently earns traffic or holds links, and you decide exactly where each one lands on the new site. Each old URL gets a 301 redirect to its closest match. A 301 tells search engines the page moved permanently and passes its accumulated authority to the new location.
Two mistakes to avoid here. First, redirecting everything to the homepage instead of the matching page, which throws away the specific relevance each URL earned. Second, redirect chains, where one URL points to another that points to a third. Chains slow crawling and dilute the signal, and long enough ones can stop pages resolving at all. Map old straight to new, in a single hop.
The difference between a migration that costs you traffic and one that quietly improves it is almost entirely in the preparation, not the platform.
Carry the metadata and content across deliberately
Title tags, meta descriptions, heading structure, image alt text, and structured data are part of why a page ranks. When a rebuild starts from a clean template, these are easy to forget, and a page that loses its title tag can lose its position. Treat the existing metadata as content to migrate, not decoration to redo from scratch. The same goes for the body copy: if a page ranks, the words on it are doing work, so preserve them unless you are deliberately improving them.
Record a baseline before you touch anything
You cannot tell whether a migration went well if you never wrote down where you started. Before launch, record your current rankings for the queries that matter, your organic traffic by page, and your most valuable backlinks. This baseline is what lets you confirm, in the weeks after launch, that nothing slipped, and to catch it quickly if something did. Skipping this step is how a slow leak goes unnoticed for months.
Find the pages that carry the weight
Not every URL matters equally. A handful of pages usually drive most of the organic traffic and hold most of the inbound links. Find them, and protect them first. Their redirects, metadata, and content deserve individual attention rather than being swept along with everything else in a bulk move.
Test before launch, then watch after
Before the switch, crawl the new site on a staging URL and check that redirects resolve, internal links work, and no important page returns an error. After launch, keep watching: track crawl errors, indexing status, rankings, and traffic for several weeks. Redirects are not a one-time task you tick off and forget. They are infrastructure that has to keep working as the site evolves.
Done right, a migration can help
Handled properly, a migration is not just damage avoided. A cleaner architecture, tidier URLs, and a faster site can improve organic performance over the following months. We saw this on a UK real-estate migration: an ageing .NET website moved to WordPress with the CRM integrated, content and SEO carried over intact, and the business kept running throughout. The move was planned so nothing important was left to chance, and it went live within a month.
That is the whole point of doing the boring parts well. If you are weighing up a move, our website modernization service exists for exactly this, and the FAQ answers the cost and timeline questions people usually ask first.
Leo Tech Labs is a consulting-led software firm. We plan migrations so the business keeps running while the ground moves under it, and so the rankings come with you.