← All apps Upsell CartBot vs Ultimate Sales Boost
🔬 Lab Findings 🔧 Stack Builder
⚡ Faster
B
CartBot
58.01 KB · 5 ms CPU
★ 4.9 · 475 reviews
Acceptable
VS
D
Ultimate Sales Boost
645.46 KB · 55 ms CPU
★ 4.8 · 1,418 reviews
Critical
Metric CartBot Ultimate Sales Boost
Overall Grade B D
JS Payload 58.01 KB 645.46 KB
CPU Desktop 5 ms 55 ms
CPU Mobile 29 ms 318 ms
Layout Shift 0 0.0006
Merchant Rating ★ 4.9 (475) ★ 4.8 (1,418)
Install CartBot → Grade B · 58.01 KB · Faster option in this comparison
Install Ultimate Sales Boost → Grade D · 645.46 KB · View full review: Ultimate Sales Boost
⚡ Lab-Verified Fix Keep Ultimate Sales Boost and reduce its speed impact with a dedicated script optimizer: View Booster Page Speed Lab Report →

CartBot vs Ultimate Sales Boost: Shopify Performance Comparison

CartBot wins with Grade B vs Grade D — a significant performance difference that compounds on mobile devices.

Both apps provide post-purchase upsell and cross-sell 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

MetricCartBotUltimate Sales BoostFaster
Overall GradeBDCartBot
JS Payload58.01 KB645.46 KBCartBot
CPU Desktop5 ms55 msCartBot
CPU Mobile29 ms318 msCartBot
Layout Shift0.00.0006CartBot

Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-30.

CartBot — The Faster Option (Grade B)

CartBot scores Grade B with a JS payload of 58.01 KB and 5 ms desktop CPU execution. Mobile CPU: 29 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 CartBot speed report →

Ultimate Sales Boost — The Heavier Option (Grade D)

Ultimate Sales Boost scores Grade D with a JS payload of 645.46 KB and 55 ms desktop CPU execution. Mobile CPU: 318 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 Ultimate Sales Boost speed report →

When to Choose CartBot

When to Choose Ultimate Sales Boost

Performance Verdict

Winner: CartBotCartBot wins with Grade B vs Grade D — a significant performance difference that compounds on mobile devices.

Install CartBot →

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.