HTML onblur Attribute

Last Updated : 31 Jul, 2026

This attribute fires at that moment when the element loses focus. This attribute is mostly used in the Form validation code. This attribute is the opposite of onfocus attribute.

Supported Tags: It supports all HTML elements except these elements which are given below : 

  • <base>
  •  <bdo>
  •  <br>
  •  <head>
  •  <html>
  •  <iframe>
  •  <meta>
  •  <param>
  •  <script>
  •  <style>
  •  <title>

Syntax

<element onblur = "script">

Attribute Value: This attribute is used to any HTML elements. The script run when onblur attribute called.

Example: In this example we use the onblur attribute to call a JavaScript function that converts the input text to uppercase when the user leaves the input field.

html 
<!--Driver Code Starts-->
<!DOCTYPE html>
<html>
<head>
    <title>onblur attribute</title>
    <style>
        body {
            text-align: center;
        }
        h1 {
            color: green;
        }
    </style>
</head>
<body>
    <h1>GeeksforGeeks</h1>
    <h2>onblur attribute</h2>
    <!-- When leave the input box then the input box 
        value is converted into capital letter. -->
<!--Driver Code Ends-->

    Username: <input type="text" 
                     name="fname" 
                     id="GFG" 
                     onblur="Geeks()">
    <script>
        function Geeks() {
            let y = document.getElementById("GFG");
            y.value = y.value.toUpperCase();
        }
    </script>

<!--Driver Code Starts-->
</body>

</html>
<!--Driver Code Ends-->
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