Developer Tools

Color Contrast Checker

Check color contrast ratio for WCAG 2.1 AA and AAA compliance. Live preview with foreground and background color pickers.

Colors

Foreground

Background

Normal Text Sample

This is small body text for readability testing.

WCAG Result

AA Normal

AA Large

AAA Normal

AAA Large

WCAG 2.1: AA requires 4.5:1 (normal) / 3:1 (large). AAA requires 7:1 / 4.5:1.

Chmod Calculator

Calculate Unix file permissions visually. Click checkboxes to set read/write/execute for owner, group, and others. Shows octal and symbolic notation.

CSS Specificity Calculator

Calculate CSS selector specificity and understand which styles take precedence. Supports ID, class, attribute, pseudo-class, element, and pseudo-element selectors.

CSS Unit Converter

Convert between CSS units: px, rem, em, pt, vw, vh. Set custom base font size and viewport width.