HTML DOM getElementById() Method

Last Updated : 28 Jul, 2025

The getElementById() method returns the elements that have given an ID which is passed to the function. This function is a widely used HTML DOM method in web designing to change the value of any particular element or get a particular element. If the passed ID to the function does not exist then it returns null.

Note: Each ID needs to be unique. If there are multiple elements with the same ID, only the first one will be returned.

Syntax:

document.getElementById( element_ID )

Parameter:

This function accepts single parameter element_ID which is used to hold the ID of the element.

Return Value:

It returns the object of the given ID. If no element exists with the given ID then it returns null.

Example 1: This example describes the getElementById() method where element_id is used to change the color of the text on clicking the button.

HTML

<!DOCTYPE html> <html> <head> <title> DOM getElementById() Method </title> <script>  // Function to change the color of element  function geeks() {  let demo = document.getElementById("geeks");  demo.style.color = "green";  }  </script> </head> <body style="text-align:center"> <h1 id="geeks">GeeksforGeeks</h1> <h2>DOM getElementById() Method</h2> <!-- Click on the button to change color --> <input type="button" onclick="geeks()" value="Click here to change color" /> </body> </html>

Output:

Example 2: This example describes the getElementById() method where the element_id is used to change the content on clicking the button.

HTML

<!DOCTYPE html> <html> <head> <title> DOM getElementById() Method </title> <script>  // Function to change content of element  function geeks() {  let demo = document.getElementById("geeks");  demo.innerHTML = "Welcome to GeeksforGeeks!";  }  </script> </head> <body style="text-align:center"> <h1>GeeksforGeeks</h1> <h2>DOM getElementById() Method</h2> <h3 id="geeks">Hello Geeks!</h3> <!-- Click here to change content --> <input type="button" onclick="geeks()" value="Click here to change content" /> </body> </html>