String.prototype.toLowerCase()
Returns the calling string converted to lowercase.
Syntax
str.toLowerCase()Returns
string — A new lowercase string.
Examples
console.log('HeLLo'.toLowerCase());
Output
hello
console.log('ABC123'.toLowerCase());
Output
abc123
Notes
Uses locale-independent Unicode case mappings. For locale-aware conversion use
`toLocaleLowerCase`. Commonly used for case-insensitive comparisons. Does not
mutate the original.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 1.0 |
| firefox | 1.0 |
| safari | 1.0 |
| edge | 12 |
| node | 0.10 |