Shopify Quick Buy & Fast Checkout: When to Skip the Cart and Go Straight to Pay

The default Shopify journey is: PDP → Add to Cart → Cart Drawer → Checkout. Four steps. For high-intent shoppers buying a single item, two of those steps are pure friction.

A Shopify Quick Buy button (also called “Buy Now,” “Express Buy,” or “Fast Checkout”) collapses the journey to PDP → Checkout. One step. In our data, adding it lifts conversion 4-9% on single-SKU and impulse purchases — without hurting AOV on basket-builders.

This guide covers when Quick Buy works, when it doesn’t, where to place it, and how to add one to your Shopify store.

What is a Shopify Quick Buy / Buy Now button?

A secondary CTA next to “Add to Cart” that takes the shopper directly to Shopify Checkout with the current product/variant in the cart. It bypasses:

• The cart drawer (no review step)
• Any cart-page upsells
• Any rewards-bar friction

Some implementations also pre-select Shopify Pay or Shop Pay for one-tap checkout, dropping the journey to a single tap.

When Quick Buy lifts conversion

Quick Buy shines in five scenarios:

1. Single-SKU stores. If 80%+ of your orders are single-item, the cart is just a delay. A Quick Buy button on every PDP collapses the funnel.

2. Restocks. Returning shoppers buying the same product they’ve bought before don’t need a cart review. Quick Buy + saved Shop Pay = 1-tap reorder.

3. Gift-with-purchase reorders. Shoppers who already know what they want.

4. Mobile traffic. Mobile checkout completion drops 4-7% per extra tap. Quick Buy removes one tap entirely.

5. Low-AOV stores. When the average cart is one item at under $50, you’re not losing AOV by skipping the cart — and you’re gaining the conversion.

When Quick Buy doesn’t belong

On stores with strong AOV-lifting upsells. If your cart drawer’s recommendation engine adds 15%+ to AOV, sending shoppers around it costs more than it saves.

On bundle-driven categories. Skincare, supplements, apparel collections — anywhere shoppers naturally build baskets — Quick Buy hurts more than it helps.

As the only CTA. Always pair Quick Buy with regular Add to Cart so shoppers can still build a multi-item order.

Where to put the Quick Buy button

Two strong placements:

1. Below the buy box (paired with Add to Cart)

The most common pattern. Two buttons side-by-side or stacked:

[Add to Cart]
[Buy Now →]

Shoppers who want to keep browsing tap “Add to Cart.” Shoppers ready to pay tap “Buy Now.” No friction either way.

2. On collection / category pages

A small “Buy Now” link on each product card on collection pages. Best for stores selling impulse SKUs or accessories where shoppers know what they want before they reach the PDP.

This pattern is especially powerful on mobile collection grids, where each product card is competing for attention.

Quick Buy + cart drawer: the hybrid pattern

The most elegant pattern uses both:

• Add to Cart opens the cart drawer (with upsells, rewards, FBT)
• Buy Now skips straight to checkout

Same product page, two distinct flows for two distinct shopper intents. The data is consistent: stores that ship both convert ~6% better than stores that ship only one.

Sticky add-to-cart bar + Quick Buy

The mobile sticky add-to-cart bar should usually contain both buttons:

[Image] Product Name              [Add] [Buy Now]
        $24.99

This gives mobile shoppers the same choice they’d have in the buy box, even when they’ve scrolled past it.

Designing the Quick Buy button

A few patterns from auditing dozens of Shopify themes:

• Make it visually secondary to Add to Cart. Outline button vs. filled, or a slightly muted color. Shoppers shouldn’t tap it accidentally.
• Use an action verb. “Buy Now,” “Checkout Fast,” or “Get it now” — not just “Quick Buy” (which is jargon).
• Add an arrow. “Buy Now →” telegraphs that something happens after the tap.
• Don’t show a confirmation modal. That defeats the purpose. Ship them straight to Shopify Checkout.

Quick Buy with variant selection

The tricky case: a product with multiple sizes/colors. Two patterns:

Pattern A: require a variant first. Disable the Quick Buy button until a variant is selected. Standard, predictable.

Pattern B: open a mini variant picker. Tapping Quick Buy opens a small modal: pick size/color, then proceed to checkout. Best for collection-page Quick Buy where the variant isn’t selected yet.

Cartylabs supports both. We recommend Pattern A on PDPs (where the buy box already has variant pickers) and Pattern B on collection grids.

How to add Quick Buy to Shopify

The hard way: edit your theme to add the button markup, write JS to call Shopify’s Cart API and redirect to /checkout, handle variant edge cases, and ship a separate mobile UI. Plan for an afternoon plus theme update breakage.

The easy way: use a Shopify cart app that ships Quick Buy via App Embed. Cartylabs includes Quick Buy Now buttons on PDPs, collection grids, and the sticky add-to-cart bar — toggle from the dashboard, no theme edits.

Measuring Quick Buy impact

The right test: 50/50 traffic split for 2 weeks. Compare:

Metric	Expected change
Overall conversion rate	+2-5%
Mobile conversion rate	+4-9%
AOV	-5% to +3% (depends on cart-drawer upsells)
Cart abandonment rate	-3 to -7 percentage points
Time to checkout (mobile)	-30 to -60 seconds

The AOV signal is the one to watch. If your cart drawer is doing real AOV work and Quick Buy bypasses it, your AOV will dip — but conversion lift usually offsets it for revenue-positive net.

A short summary

A Shopify Quick Buy / Fast Checkout button is a near-free conversion lift for stores with a meaningful share of single-SKU or impulse purchases. Pair it with the standard Add to Cart so shoppers building larger baskets aren’t forced past your upsells.

Want it on your store? Install Cartylabs free on Shopify — Quick Buy Now is included in every plan, with a 14-day free trial.