How to Replace Space with Underscore in PHP

• Tech Area
• Last updated on: January 8, 2026

I am working on a project where I need to replace white space with underscore. How do I achieve in PHP. In this tutorial, We will learn how to replace white space from string with underscore using the PHP inbuilt function. By the using of str_replace() function we can replace white space from string.

Solution

<?php
$str = "Hello Welcome to Tech Area";
$str = str_replace(' ','_',$str);         //Replace Space with Underscore
echo $str;
?>

Output

Hello_Welcome_to_Tech_Area