ExtensionKit ‑ Custom Checkout

Customize your checkout and create advanced discount rules

by Maverick Apps · Launched: September 2024 · Free plan available.

5.0 (2) on Shopify Built for Shopify

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Supercharge your checkout with upsells, custom fields, discounts, cart validations & more

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About ExtensionKit ‑ Custom Checkout

Unlock the full potential of your Shopify checkout with Extension Kit. Generate revenue with product upsells and subscription upgrades, and collect additional information from customer's with custom fields. Easily customize checkout pages using drag-and-drop blocks for banners, images, and informational text. Customizable for all of your customer's with Shopify Markets. Advanced discounts powered by Shopify Functions. Checkout customizations built for Shopify Plus plans only. Checkout product upsells, subscription upgrades, banners, custom fields & more Create tiered product or order discount promotions Schedule blocks and discounts for timed promotions Limit quantity of items in the cart Compatible w/ Shopify B2B & Shopify Markets for translations and multi-currency Show more Show less

Last verified: July 16, 2026 · Fresh

App details

Developer: Maverick Apps
Category: Marketing & conversion
Pricing: Free plan available
Launched: September 2024
Rating: 5.0 (2) on Shopify

Key features

Content and upsell checkout extensions
Advanced discount
Cart validations
Checkout branding editor
Email support

Integrations with:

Checkout, Shopify Admin

4 plans · starts free · 14-day free trial

Startup

Free

Small Business

$19.99/month

Growth

$49.99/month

Enterprise

$99.99/month

Plans and prices as listed on the Shopify App Store.

Ratings & reviews

based on 2 Shopify App Store reviews

Use the arrows to read individual reviews

We use this app daily to showcase a variety of products, and the product upsell feature has been a game changer! It made adding relevant products at checkout effortless, and since utilizing this app we have seen a major boost in sales. The setup was quick, everything runs smoothly, and the upsells feel natural and not pushy. It has been a great way to show customers products that can complete thei...

— GALLERY DEPT.

The Extension Kit app has really helped with transitioning to the new checkout. It made the whole process a lot simpler and has been useful for migrating away from Shopify's Script Editor app. It's saved our team a ton of time, and I’d definitely recommend it to anyone using Shopify Plus!

— Pura Vida Bracelets

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