Here is a number that should change how you think about your website: over 60 percent of all web traffic now comes from mobile devices. For local businesses, that number is even higher. When someone searches for a service on their phone while sitting in their car or walking down the street, your website is the first impression. And if it does not work well on that five-inch screen, they are gone in seconds. A poor mobile experience is one of the clearest signs your website is costing you customers.
Yet I still see businesses paying thousands of dollars for custom websites that look great on a 27-inch monitor and fall apart on a phone. Tiny text that requires pinching to read. Buttons too small to tap. Navigation menus that cover the entire screen. Contact forms that are nearly impossible to fill out with a thumb. These are not edge cases. They are the majority of custom websites built by designers who still think desktop-first.
After 25 years of building websites for small businesses, I can tell you that mobile-friendly is not a feature. It is the foundation. Let me walk you through what to look for in a designer, how to evaluate their work, and what separates a genuinely mobile-first website from one that was simply crammed onto a smaller screen.
The term "mobile-friendly" gets used loosely. Many designers will tell you their sites are mobile-friendly because they use responsive frameworks. But responsive and mobile-friendly are not the same thing. Understanding the difference will save you from paying for a site that technically resizes but practically fails your mobile visitors.
Responsive design means a website adjusts its layout based on screen size. A three-column desktop layout becomes a single column on a phone. Images shrink. Text reflows. This is table stakes in 2025 — any designer not building responsive sites is a decade behind.
But responsive design alone does not make a site mobile-friendly. A page can be responsive and still have a five-second load time on a cellular connection. It can be responsive and still have form fields that are painful to use on a touchscreen. Responsive is a technical capability. Mobile-friendly is a user experience.
Mobile-first design means the website is designed for the phone screen first, then progressively enhanced for tablets and desktops. This is a fundamentally different process. When you design for the smallest screen first, you are forced to make hard decisions about what actually matters. What content does a visitor need immediately? What actions should be easiest to take? What can be simplified or removed entirely?
The result is a cleaner, faster, more focused website at every screen size. Desktop users benefit too, because the discipline of designing small first eliminates the bloat and clutter that desktop-first designers tend to add because they have the space.
Google switched to mobile-first indexing in 2019. That means Google evaluates the mobile version of your website — not the desktop version — when deciding where to rank you in search results. This is a core part of why SEO services must account for mobile performance. If your mobile site is slow, hard to use, or missing content that exists on desktop, your search rankings suffer regardless of how polished your desktop experience is.
Google's Core Web Vitals — the performance metrics that directly affect rankings — are measured separately for mobile and desktop. A site that scores 95 on desktop and 40 on mobile is a site with a mobile problem that is costing you search visibility every single day.
Every designer will claim they build mobile-friendly websites. Here is how to verify that claim before you spend a dollar.
This is the simplest and most revealing test. Pull up the designer's website on your phone and use it as a visitor would. Is the text readable without zooming? Can you navigate easily with your thumb? Does the page load quickly? Can you find their contact information within five seconds? If their own website does not work well on mobile, they will not build one that works well for you.
Do not just look at portfolio screenshots on a desktop monitor. Open every portfolio piece on your phone and actually use it. Fill out a contact form. Browse the navigation. Scroll through the content. This is what your customers will do with your site. If the designer's portfolio sites are clunky on mobile, that is the quality you are buying.
Google's PageSpeed Insights tool scores any website on both mobile and desktop performance. Enter the URLs of the designer's portfolio sites and look at the mobile scores specifically. A good mobile score is 80 or above. A score below 50 means serious performance problems. Pay attention to the Core Web Vitals assessment — it will tell you whether the site passes or fails Google's real-world performance thresholds.
A designer who truly works mobile-first will describe their process differently than one who designs desktop-first and makes it responsive. Ask these questions:
Designing in a browser's responsive mode is not the same as testing on actual phones. Browser emulation misses touch interactions, real-world network speeds, and device-specific rendering quirks. Ask whether they test on physical devices during development. A designer who keeps a few different phones and tablets on their desk for testing takes mobile seriously.
Beyond passing technical tests, a well-designed mobile site has specific characteristics that you can identify just by using it.
Buttons and links should be at least 44 pixels tall — large enough to tap with a thumb without accidentally hitting the wrong target. Form fields should have adequate spacing between them. Dropdown menus should be replaced with simpler alternatives that work naturally with touch input. Nothing on the page should require the precision of a mouse cursor.
A mobile-friendly site loads quickly even on a 4G connection, not just on your office WiFi. This means optimized images, minimal JavaScript, efficient code, and ideally a total page weight under 1.5 megabytes. If a page takes more than three seconds to become interactive on a phone, most visitors leave before they see your content.
Body text should be at least 16 pixels on mobile. Line height should be generous — 1.6 to 1.8 times the font size. Paragraphs should be short. Headlines should be large enough to scan while scrolling. If a visitor needs to pinch-zoom to read anything on your site, the mobile design has failed.
Desktop sites can get away with mega-menus and multiple navigation levels. Mobile sites cannot. Good mobile navigation is flat, focused, and reachable with one hand. The most important pages — your services, contact information, and calls to action — should be accessible within one or two taps from anywhere on the site.
For local businesses, mobile visitors often want to call you or get directions. Your phone number should be a tappable link that opens the dialer. Your address should link to maps. These seem like small details, but they are the difference between a mobile visitor who converts and one who gives up and calls your competitor instead.
Contact forms on mobile should have large input fields, appropriate keyboard types (number pad for phone fields, email keyboard for email fields), minimal required fields, and clear error messages. A form that works fine on desktop can be unusable on mobile if the designer did not think about how people actually type on a phone.
Not every type of web designer approaches mobile the same way. Here is what to expect from each.
Small agencies that build custom sites from scratch tend to have the most control over mobile performance. Because they are writing the code themselves as part of a full web design and development engagement rather than working within platform constraints, they can optimize every aspect of the mobile experience. The trade-off is higher cost and longer timelines, but the result is a site that performs exactly the way it should on every device.
At Uncommon Web Design, every site we build starts with the mobile layout. We design and test on actual phones throughout the build process, not just at the end. The result is sites that consistently score 90 or above on mobile PageSpeed and pass all of Google's Core Web Vitals thresholds. You can see the results in our portfolio — pull up any project on your phone and test it yourself.
Some agencies focus specifically on mobile performance and progressive web app development. Companies like Appnet, Weblumino, and Incline Marketing have built reputations around mobile expertise. These firms tend to be more technical and may be a good fit if your project involves complex mobile interactions, app-like functionality, or performance requirements beyond a standard business website.
Designers who work within platforms like Squarespace, Wix, or Webflow are constrained by the platform's mobile capabilities. Modern platforms handle basic responsiveness well, but mobile performance is often mediocre because you cannot optimize the underlying code. If mobile speed and a custom experience are priorities, platform-based designers may not be the best fit.
Larger agencies like WebFX, Go Web Design, and Ecopixel offer mobile-friendly design as part of broader service packages. They typically have dedicated mobile testing teams and established processes. The downside is that you are one of many clients, and the personal attention to your mobile experience may not match what you would get from a smaller shop that stakes its reputation on every project.
Watch for these warning signs during your evaluation process:
You do not need to understand code to hire a good mobile designer, but knowing a few technical concepts helps you ask better questions and evaluate proposals.
Every mobile-friendly page needs a properly configured viewport meta tag that tells the browser how to scale the content. This is so basic that its absence indicates a designer who is not thinking about mobile at all.
A phone does not need to download a 2000-pixel-wide hero image. Good mobile design serves appropriately sized images based on the device's screen resolution, saving bandwidth and speeding up load times. Modern techniques include the srcset attribute, the picture element, and automatic format negotiation that serves WebP or AVIF to browsers that support them.
Mobile connections are slower and less reliable than desktop connections. A well-optimized mobile site inlines the CSS needed for the initial view and defers everything else. JavaScript is loaded asynchronously so it does not block the page from rendering. These techniques can cut perceived load time in half on mobile devices.
Desktop interactions rely on hover states, precise clicks, and scroll wheels. Mobile interactions rely on taps, swipes, and long presses. A mobile-first designer builds interactions for touch first and adds hover enhancements for desktop, not the other way around. This means no dropdown menus that require hovering, no tooltips that only appear on mouse-over, and no carousels that only work with click-and-drag.
At Uncommon Web Design, mobile is not a phase of the project. It is the starting point.
Every site we build follows the same process: we design the mobile layout first, build it, test it on real devices, then enhance it for tablet and desktop. This is the opposite of how most agencies work, and it produces measurably better results.
You do not have to take my word for it. Open any site in our portfolio on your phone right now. That is the experience your customers will get. Read about the results in our case studies — our clients see measurable improvements in mobile traffic, engagement, and conversions after launching with us.
For a broader guide on evaluating web designers, see our post on how to choose a web design agency.
Your customers are on their phones. More than half of them will never see your website on a desktop. The designer you hire needs to understand this not as an afterthought but as the starting reality.
Mobile-friendly is not a checkbox on a feature list. It is a design philosophy that affects every decision — from layout to typography to performance to navigation. The right designer builds for the phone first and enhances for everything else. The wrong designer builds for the big screen and hopes it shrinks gracefully. It never does.
Test everything on your phone. If a designer's own website and portfolio do not impress you on a five-inch screen, nothing else they say matters.
If you want a custom website built mobile-first from day one, start with a free consultation. I will show you exactly how the process works and what your site will look and feel like on every device your customers use.
The best desktop experience in the world means nothing if 60 percent of your visitors never see it.
Let's build something your customers will love on any device. Free consultation, no pressure.