Meta Conversions API (CAPI) Param Builder vs Microsoft Advertising UET: Shopify Performance Comparison
Both apps score Grade B — Microsoft Advertising UET has the edge with 3 ms vs 9 ms desktop CPU execution.
Both apps provide heatmaps, session recording, and analytics 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 | Meta Conversions API (CAPI) Param Builder | Microsoft Advertising UET | Faster |
|---|---|---|---|
| Overall Grade | B | B | Tie |
| JS Payload | 54.69 KB | 53.97 KB | Microsoft Advertising UET |
| CPU Desktop | 9 ms | 3 ms | Microsoft Advertising UET |
| CPU Mobile | 37 ms | 11 ms | Microsoft Advertising UET |
| Layout Shift | 0.0 | 0.0 | Meta Conversions API (CAPI) Param Builder |
Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-31.
Microsoft Advertising UET — The Faster Option (Grade B)
Microsoft Advertising UET scores Grade B with a JS payload of 53.97 KB and 3 ms desktop CPU execution. Mobile CPU: 11 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 Microsoft Advertising UET speed report →
Meta Conversions API (CAPI) Param Builder — The Heavier Option (Grade B)
Meta Conversions API (CAPI) Param Builder scores Grade B with a JS payload of 54.69 KB and 9 ms desktop CPU execution. Mobile CPU: 37 ms. Performance is acceptable but worth monitoring, particularly on stores with high mobile traffic share.
View full Meta Conversions API (CAPI) Param Builder speed report →
When to Choose Meta Conversions API (CAPI) Param Builder
- 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
When to Choose Microsoft Advertising UET
- 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
Result: Comparable — Both apps score Grade B — Microsoft Advertising UET has the edge with 3 ms vs 9 ms desktop CPU execution.
Install Microsoft Advertising UET →
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.