PHP strtolower() Function (original) (raw)

Last Updated : 11 Jul, 2025

The **strtolower() function is used to convert a string into lowercase.

**Syntax:

_string strtolower( $string )

**Parameters:

The only parameter to this function is a string that is to be converted to lower-case.

**Return value:

This function returns a string in which all the alphabets are lower-case.

**Examples:

**Input: $str = "GeeksForGeeks"
strtolower($str)
**Output: geeksforgeeks

**Input: str="goingBACKheSAWTHIS123str = "going BACK he SAW THIS 123str="goingBACKheSAWTHIS123#%"
strtolower($str)
**Output: going back he saw this 123$#%

Below programs illustrate the strtolower() function in PHP:

**Example 1:

PHP `

`

**Output:

geeksforgeeks

**Example 2:

PHP `

`

**Output:

going back he saw this 123$#%

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.