Engineering as marketing

Free tools & guides to grow your store

Calculators, builders, and plain-English guides for attribution, A/B testing, and conversion optimization. No sign-up required.

Free tools
UTM Link Builder
Create error-free GA4 and TikTok tracking links with real-time validation and campaign presets.
Popular
CRO ROI Calculator
See how much revenue you're leaving on the table by not A/B testing your landing pages.
Revenue
Pixel Generator
Generate clean conversion snippets for GA4, Meta, and TikTok in seconds.
Dev tool
Significance Calculator
Check whether your A/B test results are statistically valid (frequentist).
A/B testing
Sample Size Calculator
Work out how much traffic you need before you start a test.
A/B testing
Funnel Analyzer
Visualize drop-off points and estimate lost revenue at every stage.
Revenue
CAC Calculator
Calculate your true customer acquisition cost and payback period.
Revenue
Guides & definitions
Swipe file
50+ A/B testing ideas for online stores
Browse ideas
Interactive audit
The ultimate CRO audit checklist
Start audit
Guide
Conversion rate benchmarks by industry
Compare your rate
Glossary
What is ROAS? The definitive guide
Read definition
Analytics
Why GA4 misses a chunk of your revenue
Read guide
Attribution
Multi-touch attribution vs last-click
Read guide