Have you ever watched a customer browse your product page, scroll through your photos and description, then leave without buying? One common reason: by the time they decide to purchase, the "Add to Cart" button has scrolled out of view. A sticky add to cart button fixes this by keeping the buy button visible no matter where a customer is on the page.
This small change can have a noticeable impact on your store's conversion rate. Here is how to set one up on your Shopify store, why it works, and what to keep in mind.
A sticky add to cart button is an element that stays fixed on screen — usually at the bottom of the page or as a floating bar — as a customer scrolls through a product page. Instead of forcing shoppers to scroll back up to find the "Add to Cart" button, it remains accessible at all times.
You have probably seen this pattern on major e-commerce sites like Amazon and Nike. It removes friction from the buying process and makes it easier for customers to act the moment they decide to purchase.
On mobile devices especially, product pages can get long. Between multiple product images, variant selectors, description text, reviews, and related products, the original add to cart button can be hundreds of pixels above or below the current scroll position.
Here is what happens without a sticky button: customers scroll down, read reviews, compare variants — then need to hunt for the buy button. Every extra step between "I want this" and "I bought this" increases the chance they abandon the page. A sticky add to cart button eliminates that gap.
This matters even more on mobile, where screen space is limited and scrolling takes more effort. Since mobile traffic now accounts for the majority of Shopify store visits, keeping the buy button visible is not optional — it is practical.
There are a few ways to add this feature, depending on your technical comfort level.
Some Shopify themes include a built-in sticky add to cart option. Check your theme settings under Online Store > Customize > Product Page. Look for options like "sticky add to cart," "fixed buy button," or "floating cart button." If your theme supports it, you can enable it with one click.
Not all themes offer this, though. If yours does not, you will need an app or custom code.
The fastest and most reliable method is using a Shopify app that adds a sticky add to cart button without requiring code changes. Apps let you customize the button's appearance, position, and behavior — and they work across themes without breaking your store design.
When choosing an app, look for one that offers customization options (color, text, position), works on both desktop and mobile, loads quickly without slowing your site, and lets you control which products or pages show the sticky button.
If you are comfortable editing theme code, you can add a sticky add to cart bar using custom CSS with position: fixed styling and a snippet of Liquid code. This approach gives you full control but requires maintenance whenever you update your theme.
For most merchants, an app-based solution is the safer and faster choice.
Keep it simple. The sticky bar should show the product name, selected variant, price, and the add to cart button. Do not clutter it with extra information.
Match your store's design. Use your brand colors and fonts so the sticky bar feels like a natural part of the page, not an intrusive pop-up.
Test on mobile first. Make sure the sticky bar does not cover important content or interfere with navigation on smaller screens.
Include variant selection. If your product has multiple variants (size, color), let customers pick their option from the sticky bar without scrolling back up.
Monitor performance. After adding a sticky add to cart button, track your add-to-cart rate and conversion rate for a couple of weeks to measure the impact.
If you want to add a sticky add to cart button along with other conversion-focused tools — like countdown timers, trust badges, and free shipping bars — Boolean Conversion Kit bundles all of these features in one Shopify app. You can set up a sticky add to cart button in minutes, customize it to match your store, and pair it with other tools that work together to turn more visitors into buyers.
A sticky add to cart button is one of those changes that takes minutes to implement but pays off every day your store is open. If your customers are scrolling past the buy button, give them a reason — and a way — to click it from anywhere on the page.
