Practical Data

Conditional formatting for every web table: shades comparable columns, with the better direction figured out for you.

Data visualization with common sense: conditional formatting for every table on the web, with the direction figured out for you. Practical Data shades the comparable columns of HTML tables as you browse. Prices, ERAs and error rates go green at the low end; wins, strikeouts and population go green at the high end. Ordered labels (Low → Critical, XS → XL, Lightweight → Powerful) get their own scale. Names, years, jersey numbers and zip codes are left alone. What it does • Decides, per column, whether the values are comparable and which end is better. • Reads messy cells: footnotes, units, ranges, clock durations, placeholders. • Uses log scales when values span orders of magnitude. • Shares one scale when the same column appears in several tables. • Leaves totals rows out of the scale. • Reads tables both ways: when rows are the measures, each row gets its own scale. • Fits light and dark pages, keeping text at 5:1 contrast or better. • Hover a header for its scale. Hover a table to switch rows/columns or hide shading. Bring your own key Columns are judged by a small decision model: TypeSafe's Jev, a System One model (default), or Cloudflare's Clef. You paste your own API key in the options. A typical page costs about a tenth of a cent, and unchanged tables are never judged twice. Privacy To judge a table, the extension sends its headers, a few sample values, and the first and last rows to the provider you choose. Nothing is sent for tables you never scroll near, for sites you turn off, or for pages that opt out. Switch to "Only sites I turn on" for full control. The author runs no server and collects nothing: no analytics, no telemetry. Website: https://practicaldata.dev Open source (MIT): https://github.com/philrenaud/practical-data