High-impact tests: (1) Test big changes, not button colors, (2) Focus on high-traffic pages, (3) Have a clear hypothesis before starting, (4) Measure the metric that matters to your business. Most tests fail because they're too small to detect—go bold.
Design Principles
Test big changes
Small tweaks need huge sample sizes. Test dramatically different approaches.
One variable at a time
If you change multiple things, you won't know what worked.
Clear hypothesis
State what you expect to happen and why before running the test.
Focus on high-traffic pages
Test where you have enough visitors to reach significance.
Measure what matters
Track the metric that actually impacts your business.
Write a Good Hypothesis
A good hypothesis follows this format:
"If we [change], then [metric] will [improve/decrease] because [reason]."
Example: "If we add customer testimonials above the fold, then conversion rate will increase by 10% because social proof reduces purchase anxiety."
High-Impact Test Ideas
Value proposition
Test completely different headlines and messaging
Page layout
Radical layout changes, not just element tweaks
Pricing presentation
Different pricing tiers, anchoring, annual toggle
Social proof
Testimonials vs logos vs case studies vs none
Form design
Multi-step vs single, field count, layout
Low-Impact Tests to Avoid
- • Button color changes: Rarely significant, needs huge sample sizes
- • Minor copy tweaks: "Buy Now" vs "Purchase" won't move the needle
- • Low-traffic pages: You'll never reach statistical significance
- • Tests without hypotheses: Random changes without reasoning
Start Testing
Ready to run high-impact tests? ExperimentHQ makes it easy to test big changes with our visual editor.