How to Convert a String to Lowercase In JavaScript

We can convert a String to lowercase in JavaScript easily by using the JavaScript String toLowerCase() method.

"This is Some Text".toLowerCase();

When working with strings, it can be useful to convert a string to lowercase. A lot of the time when comparing strings, you will need to convert them both to lowercase to compare them since most comparison operators are case sensitive.

In JavaScript, we can easily convert a string to lowercase using the toLowerCase() method.

Converting a String to Lowercase In JavaScript with a Click

In this simple example, we will let the user input a string, and we will convert it to lowercase.

Here is the HTML setup:

<div id="div1">
  <label for="string1">Enter a String:</label>
  <input type="text" id="string1" name="string1">
  <div id="click-me" onclick="stringToLowercase()">Convert to Lowercase</div>
  <div id="results"></div>
</div>

We will add an onclick event to our #click-me div that will run a function we will create. Our function will first use the value property along with the getElementById method to get the string the user has entered.

We will then convert the string to lowercase using the String toLowerCase() method.

We will finally post the results using the textContent property.

function stringToLowercase(){
  
  //Get the user string
  var userString = document.getElementById("string1").value;
  
  //Convert the string to lowercase
  var lowercaseString = userString.toLowerCase();

  //Display the results
  document.getElementById("results").textContent = lowercaseString;

}

The final code and output for converting a string to lowercase in JavaScript is below.

Code Output:

Full Code:

<div id="div1">
  <label for="string1">Enter a String:</label>
  <input type="text" id="string1" name="string1">
  <div id="click-me" onclick="stringToLowercase()">Convert to Lowercase</div>
  <div id="results"></div>
</div>

<script>

function stringToLowercase(){
  var userString = document.getElementById("string1").value;
  var lowercaseString = userString.toLowerCase();
  document.getElementById("results").textContent = lowercaseString;
}

</script>

Hopefully this article has been useful for you to learn how to convert a string to lowercase in JavaScript.