If you run a Shopify D2C brand in 2025, the fastest path to higher AOV is right inside checkout. Shopify’s Checkout Extensibility lets you add pre-purchase prompts, Shop Pay enhancements, and true one-click post-purchase offers that do not slow the experience. The goal is simple: lift revenue per order while protecting the conversion that drives your paid acquisition. At Evolvingo, that balance is our thing.
Why Checkout Extensibility matters in 2025
Shopify’s native checkout is already a conversion engine. According to Shopify’s own study, Shopify’s overall conversion rate outpaces competing platforms by up to 36 percent and by an average of 15 percent, as summarized on the Shopify Checkout page. The same page explains that Shop Pay provides a one-tap experience with 4x faster completion and reports 91 percent higher mobile conversion compared to standard checkout, which is why adopting Shop Pay is often the single highest-leverage move for D2C brands.
There is also a migration reality. The legacy checkout.liquid has effectively been replaced by Checkout Extensibility. Industry summaries such as Elevar’s explainer note that checkout.liquid was sunset for the Information, Shipping, and Payment steps in August 2024, while Thank you and Order status pages have their own path. The Shopify Help Center now sets August 28, 2025 as the key deadline for upgrading Thank you and Order status pages to the new block-based, upgrade-safe versions, with details on how additional scripts and script tags are being wound down and how web pixels and blocks replace them.
One-click upsells: choose the right surface
Pre-purchase inside checkout. If you are on Shopify Plus, you can place smart offers during checkout using Checkout UI Extensions. The official Checkout UI extensions documentation clarifies that extensions at the information, shipping, and payment steps are available only to Shopify Plus stores. These targets let you surface lightweight, relevant prompts like add-on warranties or bundles without injecting custom code that could slow the page. Keep copy short, clearly price any add-ons, and respect Shopify’s UX guidelines so you do not increase friction.
Post-purchase one click. For all plans, the post-purchase page sits after payment and before the Order status page. Shopify’s guide to building a post-purchase product offer shows how to create a true one-click upsell using calculateChangeset and applyChangeset to add an item to the just-placed order. The doc notes that post-purchase checkout extensions require access approval for live stores, but are fully testable in development. This surface is powerful because the buyer is already authenticated and payment is handled, so adding the right complementary SKU typically converts better than in-cart pitches.
Thank you and Order status. With Shopify’s upgrade, these pages are now editable in the checkout and accounts editor and support app blocks and web pixels. The Plus upgrade guide describes how to replace legacy script tag customizations with blocks, which is the right place to add subtle cross-sells, referral prompts, loyalty enrollments, or subscription nudges that do not interrupt the original purchase.
Shop Pay optimization that lifts conversion instead of hurting it
Enable Shop Pay everywhere. Shopify’s Shop Pay overview states it is the highest-converting accelerated checkout on the internet and can lift conversion by as much as 50 percent compared to guest checkout. Place the Shop Pay express button prominently on the first checkout step and in the cart where appropriate, then verify the look on mobile, since that is where the largest share of conversions happen.
Add Shop Pay Installments messaging. For higher-ticket items, timely financing messaging increases comfort and AOV. The Shop Pay Installments documentation explains how to add the installments banner to product and cart forms with the payment_terms filter, and clarifies it shows dynamic disclosures and updates by variant or cart subtotal. This is a low-friction, high-trust nudge that removes price shock without extra fields.
Do less, faster. Shopify’s checkout is mobile-first, performant at scale, and supports address autocomplete, multiple payment methods, and localized experiences out of the box. The Shopify Checkout page notes capacity up to 40,000 checkout starts per minute per store, which means your tests will not collide with platform limits. Your job is to avoid clutter: one relevant offer beats three generic ones.
A safe build blueprint for D2C brands
Pre-purchase checkout prompts (Plus). Use Checkout UI Extensions to add a single, relevant offer tied to the cart context, such as a size-compatible accessory. Build with Shopify’s Polaris web components so it loads instantly and matches your brand styles automatically. The Checkout UI extensions docs detail available targets and security constraints that prevent DOM or CSS overrides, which keeps checkout safe.
Post-purchase one-click offer. Follow Shopify’s post-purchase extension tutorial to show a single SKU upsell with clear pricing and a primary accept button. The example shows how calculateChangeset computes taxes and shipping before the buyer confirms, then applyChangeset finalizes the order edit. Request access in the Partner Dashboard when you are ready for production use.
Thank you and Order status upgrades. Per Shopify’s Plus upgrade guide, re-create tracking with app pixels and replace additional scripts and script tags with blocks. This is where you can add loyalty blocks, subscription signup, or a discount for the next purchase without blocking the order confirmation.
Testing and measurement without conversion risk
Shopify’s own checkout UX guidelines emphasize maintaining trust, reducing friction, and testing across guest vs Shop Pay flows and mobile vs desktop. That means labeling prices clearly on upsells, showing components only when needed, and ensuring variants behave across surfaces. Measure the impact with clean holdout testing: ship one pre-purchase or post-purchase offer at a time, run it for a full purchase cycle, then iterate. If your ads are driving thin margins, combine checkout wins with stronger top-of-funnel creative. Evolvingo’s playbooks for breaking even on ads and building UGC that actually sells can help you fill the funnel with higher-intent traffic before you monetize it in checkout.
As a friendly reminder, if you are not on Shopify yet or you are setting up a new brand, start with Shopify and turn on Shop Pay on day one to bank the baseline conversion lift.
Need a partner to implement and profit from this?
If you want a done-for-you upgrade plan and the creative to match, Evolvingo blends strategy and execution for Shopify brands. We have shipped 75 plus campaigns, generated 4.5M plus in revenue, and helped 49 brands grow profitably. Explore our approach on the Evolvingo site, dive into our blog, or reach out to scope your checkout and Shop Pay roadmap.
Start a Shopify trial and enable Shop Pay: Shopify
Read the Break Even in 30 Days ad playbook: DTC Ad Playbook for Shopify
Fix your creatives fast: UGC That Sells
Work with us: Evolvingo contact
According to Shopify’s Checkout page, express checkouts, address autocomplete, localized experiences, and mobile-first performance are already optimized. Your edge in 2025 comes from layering upgrade-safe extensions in the right spots, following Shopify’s UX rules, and keeping every change accountable to AOV, conversion rate, and payback. That is how you add upsells and offers without hurting conversion.