HTML DOM Navigator onLine Property

The Navigator onLine property is used for returning a Boolean value which specifies whether a browser is in the online or offline mode.
It is a read-only property which returns true if the browser is in online mode or false if it is in the offline mode.

Syntax:

navigator.onLine

Return Value: A Boolean, indicating whether the browser is in online or offline mode.It returns true if the browser is online, otherwise it returns false

Below program illustrates the Navigator onLine Property :
Checking whether the browser is in the online or offline mode.

HTML

<!DOCTYPE html>
<html>
<head>
    <title>
      Navigator onLine Property in HTML
    </title>
    <style>
        h1 {
            color: green;
        }
        
        h2 {
            font-family: Impact;
        }
        
        body {
            text-align: center;
        }
    </style>
</head>

<body>
    <h1>GeeksforGeeks</h1>
    <h2>Navigator onLine Property</h2>
    
<p>
      For checking the browser's mode, 
      double click the "Check Mode" button: 
    </p>

    <button ondblclick="checkmode()">
      Check Mode
    </button>

    <p id="mode"></p>

    <script>
        function checkmode() {

            // We use navigator.onLine to check if browser is online
            var o = 
                "Is the browser in online mode? " + navigator.onLine;
            document.getElementById("mode").innerHTML = o;
        }
    </script>
</body>
</html>

Output:
Before clicking the button:

After clicking the button:

Supported Browsers: The browser supported by Navigator onLine are listed below:

Google Chrome 1
Edge 12
Internet Explorer 4
Firefox 1.5
Opera 3
Apple Safari 4

HTML DOM Navigator onLine Property

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