Dr Stacked Discounts on Cart vs UserWay Accessibility Widget: Shopify Performance Comparison
UserWay Accessibility Widget wins with Grade B vs Grade C — a one-grade performance difference that compounds on mobile devices.
Both apps provide general Shopify store enhancement functionality for Shopify stores. This page presents StackConflict’s independent lab results for both — measured in a clean-room environment with no other apps installed.
Head-to-Head Metrics
| Metric | Dr Stacked Discounts on Cart | UserWay Accessibility Widget | Faster |
|---|---|---|---|
| Overall Grade | C | B | UserWay Accessibility Widget |
| JS Payload | 213.87 KB | 112.17 KB | UserWay Accessibility Widget |
| CPU Desktop | 16 ms | 12 ms | UserWay Accessibility Widget |
| CPU Mobile | 67 ms | 83 ms | Dr Stacked Discounts on Cart |
| Layout Shift | 0.0 | 0.0 | Dr Stacked Discounts on Cart |
Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-31.
UserWay Accessibility Widget — The Faster Option (Grade B)
UserWay Accessibility Widget scores Grade B with a JS payload of 112.17 KB and 12 ms desktop CPU execution. Mobile CPU: 83 ms. It passes every StackConflict threshold for payload, CPU, and layout stability — making it safe to install on any storefront including mobile-first stores where Time-to-Interactive directly impacts conversion.
View full UserWay Accessibility Widget speed report →
Dr Stacked Discounts on Cart — The Heavier Option (Grade C)
Dr Stacked Discounts on Cart scores Grade C with a JS payload of 213.87 KB and 16 ms desktop CPU execution. Mobile CPU: 67 ms. This places it in the heavier half of StackConflict’s benchmark dataset — merchants running mobile-first stores should evaluate whether the feature value justifies the performance tradeoff.
View full Dr Stacked Discounts on Cart speed report →
When to Choose Dr Stacked Discounts on Cart
- Its unique feature set has no lighter equivalent in StackConflict’s database
- Your store traffic is predominantly desktop
- You have already removed or lightened other heavy scripts to compensate
When to Choose UserWay Accessibility Widget
- You need its specific features and can monitor its mobile impact
- Your other apps are lightweight (Grade A) so there is headroom
- You are on desktop-skewed traffic where CPU cost matters less
Performance Verdict
Winner: UserWay Accessibility Widget — UserWay Accessibility Widget wins with Grade B vs Grade C — a one-grade performance difference that compounds on mobile devices.
Install UserWay Accessibility Widget →
About This Test
StackConflict measures each Shopify app in an isolated clean-room environment — a single development store, no other scripts, Playwright-controlled browser. V8 CPU cost is the ScriptDuration delta before and after injection. CLS is captured from the same browser session. Results represent the median of three independent runs with outliers removed.
Data from the StackConflict Lab. Last updated 2026-05-31.