Conversion tools

Convert anything to anything.

Nine free conversion tools across units, time, currency, color, dates, and encodings. Each on its own subdomain. Each 100% in your browser.

Tools

Unit converter

Length, weight, temperature, volume, area, speed — metric + imperial in one widget. See every unit at once.

Timezone converter

Convert between timezones with DST awareness via the browser's IANA database. Visual day-night strip.

Currency converter

30+ currencies with rates inlined at build time, refreshed daily. Show all currencies at once.

Color converter

Hex / RGB / HSL / OKLCH conversions plus eyedropper, presets, recents, and WCAG contrast checker.

Date calculator

Days between dates, add/subtract days, live countdown. Business-day mode, leap-year aware.

Unix epoch converter

Auto-detects sec / ms / µs / ns / ISO / RFC. Live now-clock and every output side-by-side.

Base64 encoder/decoder

UTF-8 safe text encoding, URL-safe variant, file → data URI. The web's most-used encoding scheme.

JSON ↔ YAML

Convert between JSON and YAML, the two most common config formats. Works both directions.

Percentage calculator

What is X% of Y, X is what percent of Y, and percent increase or decrease between two numbers — plain-English answers.

Checking text colors for accessibility? Try the WCAG contrast checker.

Guides

Practical notes on the conversions worth knowing.

Don't see the converter you need?

We're shipping new converters constantly. The fastest way to get one built is to request it — a 30-second form. No long form. No marketing list. Just tell us what you need and why.