Chart Builder
Point it at any dataset, choose an x, a y, and a grouping, and get a chart that follows the rules — one axis, direct labels, a real legend, and a table view underneath.
Tools
Seven tools that run entirely inside your browser tab. They work on every dataset in the library, and on your own CSV — which stays on your machine.
Data Explorer
A fast table with per-column profiling: type inference, missing counts, distinct values, quantiles, and a sparkline distribution for every numeric column.
SQL Playground
Write real SELECT queries against any dataset here and get results instantly — joins, aggregates, GROUP BY, HAVING and ORDER BY, with plain errors for the things it does not support.
Distribution Lab
Sample from seven distributions, watch the central limit theorem happen at whatever sample size you choose, and see exactly when the mean stops being a useful summary.
Correlation Explorer
A diverging heatmap of every numeric pair in a dataset, with a click-through scatter so you can check whether the number is telling the truth.
Regression Lab
Fit an ordinary least squares line to any pair of columns and get the diagnostics that decide whether the fit means anything: residual plot, R², standard errors, and leverage.
Experiment Calculator
Sample size before you launch, and a confidence interval after you stop. Both directions, with the assumptions written on the screen rather than buried in a footnote.
Every chart here follows the same rules: one y-axis and never two, colour tied to the entity rather than its rank, a legend above one series, and a data table underneath. The palette was validated for colour-vision deficiency rather than eyeballed.