Free Tools
Free tools for
marketers and analysts
Calculators, models, and utilities built by Jarrah's analytics team and made free for everyone. From A/B test sizing to predictive LTV, media mix modelling, and data infrastructure — tools that cover the full stack of modern marketing analytics.
Statistical Significance Calculator
Enter your control and variant conversion data to find out if your A/B test results are real — not luck. Get instant p-values, confidence intervals, and relative uplift.
- p-value (two-proportion z-test)
- Confidence interval on the difference
- Relative uplift %
- Pass/fail verdict at 90%, 95%, or 99% confidence
A/B Test Power Calculator
Calculate how many visitors you need per variant before you start testing. Set your baseline rate, minimum detectable effect, and confidence level — get sample size and estimated runtime.
- Required visitors per variant
- Total visitors needed
- Estimated test runtime (if daily traffic provided)
- Supports relative and absolute MDE
Google Ads MCP Server
Connect your Google Ads account to Claude, Cursor, or any MCP-compatible AI assistant. Query campaign metrics, keyword Quality Scores, Keyword Planner data, and ad creative — without leaving your workflow.
- Campaign metrics: spend, clicks, impressions, impression share
- Keyword Quality Scores with component breakdowns
- Keyword Planner: ideas from seeds or URL, historical volume
- Ad creative, conversion tracking, and custom GAQL queries
GTM Page Speed Impact Test
Measure how much Google Tag Manager is costing your page speed. We run two Lighthouse tests — with and without GTM — and email you a report showing the exact performance impact.
- Performance score delta (with vs without GTM)
- Total Blocking Time reduction
- Time to Interactive improvement
- Full metrics comparison (LCP, FCP, CLS, Speed Index)
Work with Jarrah
Need more than a tool?
These tools are built from the work we do every day for clients. If you need the full analytical program — attribution, experimentation, media mix, or predictive modelling — that's what we do.
See our CRO work →