Check any color pair's WCAG contrast ratio with AA/AAA verdicts for normal and large text. Prove 4.5:1 before shipping — free, local, no signup.
Content reviewed October 2026 · About Toolzum
Convert colors between HEX, RGB, and HSL with a type-and-convert text UI. Translate brand specs across formats — free, local, no signup.
Design CSS borders visually — width, style, color, and radius with live preview and copy-ready code. Prototype a card border in 30 seconds — free, local, no signup.
Generate shade and tint scales from any base color — 10-step ramps for design systems. Build hover states systematically — free, local, no signup.
Check the contrast ratio between two colors against WCAG AA and AAA standards. Essential for accessible web design. Input never leaves your device — everything runs locally in your browser.
Check A/B test significance — conversion lifts that are real vs noise. Stop shipping coin flips — free, local, no signup.
4.5:1 for normal text (AA), 3:1 for large text and UI components, 7:1 for AAA. Test body copy at AA minimum always.
Darken text or lighten background incrementally — small moves cross thresholds. The tool suggests nearest passing shades.
18pt+ regular or 14pt+ bold qualifies for the 3:1 bar. Headlines pass where body fails — test both.
No — math runs locally in your browser. Nothing leaves your device.
Color Blindness Simulator
Simulate color blindness: preview designs through protanopia, deuteranopia, and tritanopia filters — catch invisible-to-some UI. Fix red-green errors before users suffer — local Canvas work, free, no signup.
Color Converter
Convert colors between HEX, RGB, and HSL with a type-and-convert text UI. Translate brand specs across formats — free, local, no signup.
Color Picker
Pick colors from a visual spectrum or enter hex values. Copy to clipboard — perfect for design palettes, CSS variables, and UI mockups. Work never leaves your device — everything renders locally in your browser.