10 free tools — no account required.
Find X% of Y, what percent X is of Y, or percentage change.
Calculate your exact age in years, months, and days.
Convert between military time and standard 12-hour time.
Convert between Celsius and Fahrenheit instantly.
Convert millimeters to inches and back.
Convert kilograms to pounds and back.
Format, beautify, and validate JSON instantly.
Generate random UUID v4 values — single or bulk.
Encode text to Base64 or decode Base64 to plain text.
Pick a color and convert between HEX, RGB, and HSL.