JavaScript (ES2026) reference · Number Methods and Properties

JavaScript Number.parseFloat() Method

Parse a decimal number from the start of a string, ignoring trailing text. Same as the global parseFloat().

JavaScript (ES2026) Since ES2015

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Syntax

Number.parseFloat(string)

Parameter	Description
`string`	The text to parse.

A number or NaN.

Parse a leading numberTry it yourself

console.log(Number.parseFloat("3.14 meters"), Number.parseFloat(".5"), Number.parseFloat("abc"));

Output

3.14 0.5 NaN

parseFloat() vs Number()Try it yourself

console.log(Number.parseFloat("12px"), Number("12px"));

Output

12 NaN

Version	Change
JavaScript ES2015	Added

Number.parseInt() · Parse an integer from the start of a string in a given base (radix). Always pass the radix, usually 10.
parseFloat() · Parse a decimal number from the start of a string, stopping at the first character that can't be part of it.
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