The trimStart() method removes whitespace from the beginning of a string and returns a new string, without modifying the original string. trimLeft() is an alias of this method.

Try it




Return value

A new string representing str stripped of whitespace from its beginning (left side). Whitespace is defined as white space characters plus line terminators.

If the beginning of str has no whitespace, a new string is still returned (essentially a copy of str).


After trim() was standardized, engines also implemented the non-standard method trimLeft. However, for consistency with padEnd(), when the method got standardized, its name was chosen as trimStart. For web compatibility reasons, trimLeft remains as an alias to trimStart, and they refer to the exact same function object. In some engines this means: === "trimStart";


Using trimStart()

The following example trims whitespace from the start of str, but not from its end.

let str = "   foo  ";

console.log(str.length); // 8

str = str.trimStart();
console.log(str.length); // 5
console.log(str); // 'foo  '


ECMAScript Language Specification
# sec-string.prototype.trimstart

Browser compatibility

BCD tables only load in the browser

See also