How to include an external JavaScript inside an HTML page?

JavascriptWeb DevelopmentFront End Scripts

The HTML <script> tag is used for declaring a script within your HTML document. Through this, you can define client-side JavaScript. But, what if you want to add external JavaScript inside an HTML Page? Well, you can easily do that too using the src attribute of the <script> tag.

The following are the attributes of the <script> tag −

Attribute
Value
Description
async
async
Specifies that the script is executed asynchronously.
charset
charset
Defines the character encoding that the script uses.
defer
defer
Declares that the script will not generate any content. Therefore, the browser/user agent can continue parsing and rendering the rest of the page.
src
URL
Specifies a URI/URL of an external script.
type
text/JavaScript application/ecmascript application/JavaScript text/vbscript
Specifies the scripting language as a content-type (MIME type).

For adding external JavaScript file, we will be using the src attribute −

Let’s see the HTML file first, which will include the source for the external file source.

Example

You can try to run the following code to include external JS in HTML. The HTML file is here, with a src to the JS file myscript.js.

Live Demo

<!DOCTYPE html>
<html>
   <body>
      <h2>Alert Button</h2>
      <p>
      <External JavaScript file is myscript.js/p>
      <button type="button" onclick="sayHello()">Click</button>
      <script src="myscript.js"></script>
   </body>
</html>

To use JavaScript from an external file source, you need to write all your JavaScript source code in a simple text file with the extension ".js" and then include that file as in the above structure i.e. <script src="myscript.js"></script>
Keep the following content in myscript.js file −

function sayHello() {
   alert("Hello World")
}
raja
Published on 01-Feb-2018 15:45:06
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