Enter a number, pick a locale and decimal precision, and the tool formats it with the correct grouping separators for that region using the browser Intl API.
Regions vary: the US uses 1,000,000, many EU locales use 1.000.000, and India groups as 10,00,000 (lakh/crore).
Set the minimum and maximum fraction digits; the formatter rounds and pads to match, e.g. 2 decimals gives 3.50.
It follows the locale — a period in en-US and a comma in many European locales — so numbers read naturally for that audience.