Here is a story I hear over and over. A business redesigns its website. The new site is prettier, everyone is proud of it, and within two months the phone goes quiet. Traffic is down by half and nobody can explain why, because the site is objectively better looking than the one it replaced.
The explanation is almost never the design. It is one of a handful of technical mistakes that routinely happen during redesigns, none of them visible on the screen. If you are planning a redesign, this list is worth ten minutes of your time before you sign anything.
Changing page addresses without forwarding the old ones
Every page on your site has an address, and Google’s memory of your site is attached to those addresses. Years of accumulated ranking live there. A redesign typically reorganizes pages, so the addresses change, and if nobody sets up forwarding from each old address to its new equivalent, all of that history evaporates. Google arrives at the old addresses, finds nothing, and starts your site over from zero. Visitors following old links get error pages.
This single mistake explains more post redesign traffic collapses than everything else on this list combined. The fix costs almost nothing at build time: a forwarding map from every old address to its new home. Ask whoever is doing your redesign how they plan to handle it. If the answer is vague, that is your warning.
Deleting the pages that were quietly working
Redesigns love to simplify. Twelve pages become five, everything feels cleaner, and among the deleted pages was the one that ranked for your most valuable search without anyone realizing it. Before any redesign, get the list of which pages actually receive search traffic. Those pages either survive, or their content moves somewhere that inherits their address. Tidiness is not worth a ranking you spent four years earning.
Rewriting titles and text that were ranking
Sometimes the page survives but its content is replaced with something vaguer. The old page said “commercial lease lawyer in Montréal” and ranked for it; the new page says “Legal solutions, reimagined” because it looked better in the mockup. Google ranks you for words that appear on your pages. Strip the words, lose the ranking. Keep what was working, improve how it reads, and resist any rewrite that trades clarity for style.
Launching a slower site than the one you replaced
New designs arrive loaded with large images, animations and effects, and the modern page builders behind many redesigns generate heavy code by default. The result is routinely a site that looks better and loads slower, which hurts twice: Google measures speed as a ranking factor, and impatient visitors leave before the page appears. Speed has to be stated as a requirement up front. I explained how Google measures it, in plain language, in Core Web Vitals explained for business owners.
Leaving the “hide from Google” switch on
During construction, new sites are correctly hidden from search engines so the unfinished version does not get indexed. Forgetting to flip that switch back at launch is a classic, and it is invisible: the site looks perfect, works perfectly, and tells Google to go away on every page. Weeks pass before anyone connects the silence to the setting. If your traffic died the day a new site launched, check this first. It is one of the first things I look for in audits of recently redesigned sites.
Redesigning for taste when the problem was something else
The quiet strategic mistake: a redesign gets commissioned because the site “feels dated”, with no measurement of what the current site does well, no baseline traffic numbers, and no definition of what the new site should achieve. Six months and many thousands of dollars later, nobody can even say whether things improved. Before redesigning, write down what the current site receives and produces, and what specifically the new one must do better. Sometimes the honest answer is that you do not need a redesign at all; you need forwarding fixed, pages sharpened and the site made faster, at a tenth of the cost.
How to do it safely
A redesign done properly keeps every valuable address alive or forwarded, preserves the pages and words that rank, launches at least as fast as what it replaces, gets verified as visible to Google on day one, and is watched for a few weeks afterward so any dip gets caught early. The links between your pages deserve the same care, because they carry ranking weight of their own; the internal linking guide explains that structure. None of this is exotic. It is checklist discipline, and it is the difference between a redesign that compounds your visibility and one that resets it.
If you are planning a redesign, or recovering from one, I will look at your situation honestly through a free audit, including whether you need a rebuild at all. Details on how I work are on the services page.