Common Ninja vs POWR: Shopify Performance Comparison
POWR wins with Grade B vs Grade C — a one-grade performance difference that compounds on mobile devices.
Both apps provide all-in-one conversion optimization 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 | Common Ninja | POWR | Faster |
|---|---|---|---|
| Overall Grade | C | B | POWR |
| JS Payload | 166.14 KB | 49.54 KB | POWR |
| CPU Desktop | 38 ms | 52 ms | Common Ninja |
| CPU Mobile | 145 ms | 346 ms | Common Ninja |
| Layout Shift | 0.0006 | 0.0 | POWR |
Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-30.
POWR — The Faster Option (Grade B)
POWR scores Grade B with a JS payload of 49.54 KB and 52 ms desktop CPU execution. Mobile CPU: 346 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.
Common Ninja — The Heavier Option (Grade C)
Common Ninja scores Grade C with a JS payload of 166.14 KB and 38 ms desktop CPU execution. Mobile CPU: 145 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 Common Ninja speed report →
When to Choose Common Ninja
- 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 POWR
- 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: POWR — POWR wins with Grade B vs Grade C — a one-grade performance difference that compounds on mobile devices.
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.