Units, colors, timestamps and number bases.
The converters turn one kind of value into another: units of length, weight, temperature, volume, area, speed and data size; colours between HEX, RGB, HSL, HWB and OKLCH; numbers between binary, octal, decimal, hex and other bases; and Unix timestamps into dates and back.
Type in any field and the others update instantly, using exact official conversion factors where they exist.
Exact where the definitions are exact: an inch is exactly 2.54 cm and a pound exactly 0.45359237 kg, and those official factors are what the converter uses. Results show up to 12 significant digits.
Yes. The colour converter shows the contrast ratio between two colours and whether it passes WCAG accessibility levels.
The number of seconds since 00:00:00 UTC on 1 January 1970. The converter tells seconds from milliseconds automatically and shows the date in your time zone.