Shopify UI Extensions Development
Checkout extensions, admin blocks and post-purchase upsells built on Shopify's modern extension framework.
Shopify UI extensions let you add custom functionality to your checkout, admin and post-purchase pages — without touching core theme code.
We build checkout extensions, admin blocks and post-purchase upsells using Shopify's latest extension APIs, for both standard and Plus stores.
What UI extensions unlock
Customize checkout
Add fields, upsells, messaging and logic to your checkout (Plus).
Post-purchase upsells
Increase AOV with one-click post-purchase offers.
Custom admin blocks
Give your team custom tools right inside Shopify admin.
Future-proof
Built on Shopify's modern extension framework, not fragile hacks.
What's included
- Checkout UI extensions
- Post-purchase upsell extensions
- Admin blocks & action extensions
- Customer account extensions
- Custom fields & validation
- Metafield-driven configuration
- App setup and deployment
- Testing across devices
- Version upgrade support
- Documentation & handover
How we work
Scope
A short discovery call, then a written scope with fixed price and timeline — usually within 24 hours.
Plan & architect
We plan the structure, components and edge cases before a line of code gets written.
Build
Senior developers build in clean, documented code with staging previews at every milestone.
Launch & support
We deploy, QA on real devices and hand over with documentation plus 30 days of support.
Why Eclaimify
Fixed-price, no surprises
You get a fixed-price quote within 24 hours. No hourly billing, no scope creep.
Senior developers only
Your project is handled by senior Shopify specialists — not juniors, not outsourced.
Built to last
Clean, documented, maintainable work your team can keep building on for years.
Frequently asked questions
They're Shopify's supported way to inject custom UI into checkout, post-purchase, customer accounts and the admin — without editing theme or core code.
Need custom checkout or admin functionality?
Book a free 30-minute discovery call and we'll scope your extension.
Book a discovery call