TL;DR
Most A/B testing tools add 100-200KB to your pages, slowing load times by 200-500ms. This irony: the tool meant to improve conversions actually hurts them. Every 100ms of delay costs ~1% of conversions. Choose lightweight tools (<10KB) like ExperimentHQ to avoid this trap.
Script Size Comparison
| Tool | Script Size | Performance Impact |
|---|---|---|
| Optimizely | ~200KB | High |
| VWO | ~150KB | High |
| AB Tasty | ~120KB | Medium |
| Convert | ~80KB | Medium |
| ExperimentHQ | <5KB | Minimal |
The Cost of Slow Pages
100ms delay → 1% conversion loss
Amazon1 second delay → 7% conversion loss
Aberdeen Group3 second load → 53% mobile bounce
GoogleWhy Enterprise Tools Are So Heavy
- • Feature bloat: Personalization, heatmaps, session recording bundled in
- • Legacy code: Years of accumulated features
- • One-size-fits-all: Same script for all customers
- • No incentive: Enterprise buyers don't prioritize performance
The Solution
Use lightweight tools: ExperimentHQ is under 5KB—40x smaller than enterprise tools. Same A/B testing capabilities, minimal performance impact.