HTML <form> id Attribute

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

Example

#

An id attribute on a <form>.

Vehicle Details





<form id="vehicle-form" action="/tutorial/action.html">
  <fieldset>
    <legend>Vehicle Details</legend>

    <input type="text" placeholder="Make" name="make"><br /><br />
    <input type="text" placeholder="Model" name="model"><br /><br />
    <input type="text" placeholder="Age" name="age"><br /><br />

    <button type="submit">Submit</button>
  </fieldset>
</form>

Using id

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

The identifier must be unique across the page.

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

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


Syntax

<form id="identifier" />

Values

#

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

More Examples

A <form> with a unique id.
Clicking the button displays the value of the form's action attribute.


<form id="myform" action="/tutorial/action.html">
  <input type="text" name="firstname" placeholder="First Name">
  <input type="text" name="lastname" placeholder="Last Name">

  <button type="submit">Submit</button>
</form>
  
<br/>
<button onclick="show();">Show form action</button>

<script>
  let show = () => {
    let element = document.getElementById("myform");
    alert("Action = " + element.getAttribute('action'));
  }
</script>

Code explanation

The id attribute assigns a unique identifier for the <form> element.

Clicking the button calls JavaScript which locates the <form> using the id.

Finally, the action value of the <form> element 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

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