Gladly Customer Service vs Klara: Shopify Performance Comparison
Both apps score Grade B — Gladly Customer Service has the edge with 20 ms vs 20 ms desktop CPU execution.
Both apps provide helpdesk and customer support 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 | Gladly Customer Service | Klara | Faster |
|---|---|---|---|
| Overall Grade | B | B | Tie |
| JS Payload | 132.38 KB | 41.71 KB | Klara |
| CPU Desktop | 20 ms | 20 ms | Gladly Customer Service |
| CPU Mobile | 67 ms | 65 ms | Klara |
| Layout Shift | 0.0 | 0.0 | Gladly Customer Service |
Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-30.
Gladly Customer Service — The Faster Option (Grade B)
Gladly Customer Service scores Grade B with a JS payload of 132.38 KB and 20 ms desktop CPU execution. Mobile CPU: 67 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 Gladly Customer Service speed report →
Klara — The Heavier Option (Grade B)
Klara scores Grade B with a JS payload of 41.71 KB and 20 ms desktop CPU execution. Mobile CPU: 65 ms. Performance is acceptable but worth monitoring, particularly on stores with high mobile traffic share.
View full Klara speed report →
When to Choose Gladly Customer Service
- 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 Klara
- 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 — Gladly Customer Service has the edge with 20 ms vs 20 ms desktop CPU execution.
Install Gladly Customer Service →
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.