Website design and SEO get bought separately far more often than they should be, usually because they sit with different people and different budgets. The result is familiar: a site that looks better, launches on time, and loses the search traffic that was paying for the business. The two jobs share the same objects, since URLs, page structure, copy and loading behaviour are design decisions and ranking inputs at the same time. This page explains where the overlap actually is, what happens to traffic through a rebuild, how much page experience really counts, and how to write a contract that covers both without a seam in the middle.
Why the two jobs are one purchase
Almost every artefact a redesign produces is also a search artefact. The navigation decides which pages are reachable and how importance is signalled. The URL structure decides whether existing rankings survive. The copy is what a search engine reads to decide what a page is about, and Google's guidance says creating content people find compelling and useful will likely influence a site's presence in results more than any other single suggestion it makes. The build decides loading behaviour and whether content is visible without a script running. When design and search are bought separately, these decisions get made once by the designer and then argued about later by the search provider, which is the expensive order to do it in. The cheap order is to have both parties in the room while the sitemap and URL map are being drawn, before a single template is designed.
The redesign that loses the traffic
When a rebuild changes URLs, Google's documented process is unambiguous. Map every old URL to its closest new equivalent and serve permanent redirects, which Google recommends as HTTP 301 or 308 rather than client-side alternatives. Do not funnel many old URLs to the homepage, and keep redirect chains short. Update internal links, canonical tags and sitemaps to the new addresses, remove any noindex tags or robots.txt blocks left over from staging, and make sure the server can handle the extra crawling that follows a move. Verify both the old and new sites in Search Console so the transfer can be watched: new URLs should climb in the sitemaps and indexing reports while old ones fall away. Google says that for medium-sized sites it can take a few weeks or more before the new URLs are shown instead of the old ones, and larger sites take longer, so the launch date and the trading calendar should be chosen together.
How much page experience actually counts
Google publishes a list of things it considers part of a good page experience: Core Web Vitals covering loading, interactivity and visual stability, HTTPS, mobile usability, restraint with ads and intrusive interstitials, and a clear distinction between main content and everything around it. It also publishes the caveat that matters to a redesign budget. Google says Search always seeks to show the most relevant content even where the page experience is sub-par, and that chasing a perfect score purely for search reasons may not be the best use of your time. Read together, that makes page experience a tie-breaker rather than a lever: worth fixing because slow and unstable pages cost you conversions regardless of ranking, but not worth a six-figure rebuild justified on speed metrics alone. If a proposal's entire search rationale is a performance score, ask what it expects to change about the content.
Contracting for both without a seam
Whether you hire one supplier or two, the deliverables that protect traffic have to be named and owned. Put the URL map, redirect implementation, canonical and sitemap updates, staging blocks removal, analytics and Search Console continuity, and a post-launch monitoring window into the scope in writing, with a name against each. Then apply Google's hiring guidance to whoever is doing the search side: ask for previous work, ask what results they expect and in what timeframe, insist they explain their recommendations, and treat a guaranteed ranking as a reason to stop, since Google says no one can guarantee a number one ranking. Grant read-only Search Console access during an audit rather than write access. Finally, agree who is on call in the fortnight after launch, because that is when the errors surface and the redesign team has usually moved on.
Questions people ask about website design and seo
Should the same agency do my website design and SEO?
One supplier removes the handover seam and is easier to hold responsible when traffic moves, but only if it can show real depth on both sides. Two suppliers work fine when someone on your side owns the interface and the URL map is agreed before design starts. What must never happen is a rebuild scoped without either question being asked.
Will a redesign hurt my rankings?
It can, and the risk is concentrated in URL changes. Permanent redirects from every old URL to its closest new equivalent, updated internal links, canonicals and sitemaps, and no leftover staging blocks are the mechanics that limit the damage. Google says medium-sized sites can take a few weeks or more before new URLs replace old ones in results.
Do Core Web Vitals decide rankings?
They are one of several page experience aspects Google names, alongside HTTPS, mobile usability and interstitial restraint. Google also says it aims to show the most relevant content even where page experience is sub-par, and warns against chasing a perfect score for search reasons alone. Fix them for users first.
When is the safest time to launch a rebuild?
Outside your peak trading period, with the migration checklist finished and both properties verified in Search Console. Because visibility transfers gradually rather than overnight, a launch immediately before your busiest weeks leaves no room to detect and fix a redirect error before it costs money.