Buy with Prime vs UserWay: Shopify Performance Comparison
Both apps score Grade C — UserWay has the edge with 16 ms vs 19 ms desktop CPU execution.
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 | Buy with Prime | UserWay | Faster |
|---|---|---|---|
| Overall Grade | C | C | Tie |
| JS Payload | 184.43 KB | 173.76 KB | UserWay |
| CPU Desktop | 19 ms | 16 ms | UserWay |
| CPU Mobile | 121 ms | 34 ms | UserWay |
| Layout Shift | 0.0006 | 0.0005 | UserWay |
Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-30.
UserWay — The Faster Option (Grade C)
UserWay scores Grade C with a JS payload of 173.76 KB and 16 ms desktop CPU execution. Mobile CPU: 34 ms. Even as the faster of the two options, merchants on mobile-heavy stores should weigh its impact on their combined app stack.
View full UserWay speed report →
Buy with Prime — The Heavier Option (Grade C)
Buy with Prime scores Grade C with a JS payload of 184.43 KB and 19 ms desktop CPU execution. Mobile CPU: 121 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 Buy with Prime speed report →
When to Choose Buy with Prime
- 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
- 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
Performance Verdict
Result: Comparable — Both apps score Grade C — UserWay has the edge with 16 ms vs 19 ms desktop CPU execution.
Both apps carry Grade C — see StackConflict’s full General rankings for lighter alternatives.
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 2026-05-30.