HTML <button> id Attribute

The id attribute on a <button> tag assigns an identifier to the button. The identifier must be unique across the page.

Example

#

An id attribute on a <button>.

<button id="alert-button"
        onclick="alert('The request has been approved!');">Approve</button>

Using id

The id attribute assigns an identifier to the <button> element.

The identifier must be unique across the page.

The id allows programmatic access to the <button> element.

Tip:  id is a global attribute that can be applied to any HTML element.


Syntax

<button id="identifier">

Values

#

Value Description
identifier A unique alphanumeric string. The id value must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens (-), underscores (_), colons (:), and periods (.).

More Examples

A <button> with a unique id.
Clicking the button will display its content.


<button id="mybutton"
        onclick="alert('Calculations have started!');">Calculate Revenues</button>

<br />
<button onclick="show();">Show content</button>

<script>
  let show = () => {
    let element = document.getElementById("mybutton");
    alert("Content = " + element.innerHTML);
  }
</script>

Code explanation

The id attribute assigns a unique identifier to the button.

Clicking the button calls JavaScript which locates the button using the id.

Finally, the content of the button is displayed in an alert box.


Browser support

Here is when id support started for each browser:

Chrome
1.0 Sep 2008
Firefox
1.0 Sep 2002
IE/Edge
1.0 Aug 1995
Opera
1.0 Jan 2006
Safari
1.0 Jan 2003

You may also like

 Back to <button>
Guides