Loox – Referrals vs Reviews.io: Shopify Performance Comparison
Both apps score Grade C — Loox – Referrals has the edge with 3 ms vs 8 ms desktop CPU execution.
Both apps provide product review and UGC collection 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 | Loox – Referrals | Reviews.io | Faster |
|---|---|---|---|
| Overall Grade | C | C | Tie |
| JS Payload | 274.54 KB | 391.95 KB | Loox – Referrals |
| CPU Desktop | 3 ms | 8 ms | Loox – Referrals |
| CPU Mobile | 8 ms | 33 ms | Loox – Referrals |
| Layout Shift | 0.0 | 0.0006 | Loox – Referrals |
Mobile CPU measured with 4× CDP throttle (mid-range Android). Tested 2026-05-31.
Loox – Referrals — The Faster Option (Grade C)
Loox – Referrals scores Grade C with a JS payload of 274.54 KB and 3 ms desktop CPU execution. Mobile CPU: 8 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 Loox – Referrals speed report →
Reviews.io — The Heavier Option (Grade C)
Reviews.io scores Grade C with a JS payload of 391.95 KB and 8 ms desktop CPU execution. Mobile CPU: 33 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 Reviews.io speed report →
When to Choose Loox – Referrals
- 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 Reviews.io
- 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 — Loox – Referrals has the edge with 3 ms vs 8 ms desktop CPU execution.
Both apps carry Grade C — see StackConflict’s full Reviews 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 2026-05-31.