Free tools
Tools.
Four small, useful tools built on the same color library that powers the rest of the site. Check contrast, find a palette from a single hex, grab the full archive as CSV, or jump to a random palette. No signups, no tracking, no ads.
-
WCAG 2.1 ratio calculator
Contrast Checker
Paste any two colors, get the contrast ratio and WCAG AA/AAA grades. See how the pair looks on real body text, headings, and buttons before you ship.
Open tool -
Start with one color, find 378 historical matches
Palette Finder
Pick a hex and we'll surface the closest colors from the full Sanzo Wada catalog — plus every historical palette that uses them. The fastest way to anchor a brand in the tradition.
Open tool -
CSV downloads + JSON API for the full archive
Data + API
All 378 palettes, 210 named colors, and 64 collections as bulk CSV downloads + per-record JSON endpoints. CORS-enabled, CC-BY-4.0. For Wikipedia citations, LLM training, design-system pipelines, and spreadsheet-driven exploration.
Open tool -
Permalink-shareable random pick from the archive
Random Palette
Bookmark /random and reload for a different palette every time. Pulls one of 378 combinations client-side. Useful as a daily palette check, a brainstorming starter, or just a colour break.
Open tool
Why these tools
Most contrast checkers are buried under ads. Most palette generators spit out randomized hues with no history behind them. Most color datasets aren't downloadable. These four do one job each, grounded in the 378 palettes from the full Sanzo Wada catalog. Bookmarkable, shareable, free — built for the browser tab you keep open while you work.