Mobile first: your webshop on the phone

You can check this for your own store in your Shopify analytics, where you can see your sessions by device. Then pick up your phone and try to buy something from yourself. It's the quickest test there is.

I'm Karina, founder of Design by Karina, a strategy-first boutique Shopify agency in Rotterdam for premium fashion and beauty brands. We design and build Shopify stores for brands across the Netherlands and Belgium, and we turn what makes your brand different into a reason to choose you. Before the studio I worked in product design at Uber, helping shape payment experiences for drivers, and those screens were phone screens. That's why we design for the phone first. A beautiful desktop design is great, but if it falls apart in someone's hand, what's the point?

This guide goes with our fashion and beauty webshop UX checklist.

What does mobile first mean for a webshop?

It means the decision to buy fits in one hand. Without much scrolling, someone should see the main photo, the price, the size or variant, one line that reassures them and the add to cart button. The rest of your story, like a lookbook or a longer brand text, can wait further down the page.

If someone has to pinch to zoom, hunt for their size, or lose the button behind a bar that's stuck to the screen, the page isn't mobile first yet.

Thumb reach and the buy zone

Hold your phone in one hand and notice where your thumb goes. Keep the size selector, the fit notes and the buy button in the part of the screen it reaches easily, so people don't have to change their grip right when they're about to choose.

On VYOLA, a Belgian atelier for made-to-measure body jewelry, the phone layout keeps the size chart, a field for your own measurements and the fit guarantee close to add to cart, so the size question gets settled right there. You can see it in the VYOLA case, and I go through the details in size charts that reduce returns.

Images that load and still sell

Nobody on a phone wants to wait for a photo. So keep your image files light, make sure phones get a phone-sized image, and let the first photo be honest about color and proportion, because that photo is the one people judge you on.

I'd also skip the carousel that plays on its own. On a phone it mostly costs patience. A calm gallery that people swipe through themselves feels much better. Beauty close-ups and fashion photos on a model both need to look sharp at phone width, and you don't need huge files for that.

Collections and filters on a small screen

Filters for size and color should open in a clear panel that's easy to use with a thumb. They should update the results without throwing people back to the top of the page, and show how many items are left. It helps to keep the chosen filters visible, so people can see what's on.

And if a filter gives no results, suggest a size close to it, so nobody ends up looking at an empty page.

Trust next to the button

Returns, delivery times and payment logos belong close to add to cart on a phone, not only in the footer, because on a phone the footer is a long way down.

What people want to read there depends on what you sell. Beauty buyers want to feel sure about the ingredients or how the routine works. Fashion buyers want to know about fit and returns. If you'd like to go deeper, read Building trust in your webshop and Beauty product pages.

Checkout on the phone

If you're on Shopify, you already have a checkout made for phones, so you don't have to design that part from scratch. Shop Pay helps too, because people who already use it don't have to type everything in again.

What you do decide is how much you ask. Keep the required fields to what you need, make it obvious that people can check out as a guest, and offer the payment methods your buyers expect, like iDEAL in the Netherlands, Bancontact in Belgium, and Apple Pay and Google Pay.

If you add your own fields earlier in the store, like a measurement field on a product page, make sure an error message shows up right next to that field, not at the top of a long form.

Good to know in the Netherlands

In 2025, 41% of online purchases in the Netherlands were made on a smartphone, five percentage points more than the year before, and 45% on a laptop or desktop, according to the Thuiswinkel Markt Monitor. Those are purchases, not visits, so your own sessions by device will tell you more about your store. At checkout, Dutch buyers look for iDEAL, which is moving to Wero. You'll see the iDEAL | Wero logo at checkouts now, and ABN AMRO expects iDEAL to stay available through December 2027. I wrote more about that in Shopify, iDEAL and Wero. And the button to undo a purchase, which webshops selling to consumers have needed since June 2026, has to be easy to find on a phone too.

A mobile checklist you can run this week

You don't need a designer for this. Open your mobile webshop on your own phone, go through this table and be honest. Do it before you spend more on ads, because sending more people to a store that isn't selling yet only makes that problem more expensive.