Difference between <input type='button' /> and <input type='submit' />

What is the difference between HTML <input type='button' /> and <input type='submit' />?

<input type="button" /> buttons will not submit a form - they don't do anything by default. They're generally used in conjunction with JavaScript as part of an AJAX application.

<input type="submit"> buttons will submit the form they are in when the user clicks on them, unless you specify otherwise with JavaScript.

A 'button' is just that, a button, to which you can add additional functionality using Javascript. A 'submit' input type has the default functionality of submitting the form it's placed in (though, of course, you can still add additional functionality using Javascript).

Button won't submit form on its own.It is a simple button which is used to perform some operation by using javascript whereas Submit is a kind of button which by default submit the form whenever user clicks on submit button.

It should be also mentioned that a named input of type="submit" will be also submitted together with the other form's named fields while a named input type="button" won't.

With other words, in the example below, the named input name=button1 WON'T get submitted while the named input name=submit1 WILL get submitted.

Sample HTML form (index.html):

<form action="checkout.php" method="POST">

  <!-- this won't get submitted despite being named -->
  <input type="button" name="button1" value="a button">

  <!-- this one does; so the input's TYPE is important! -->
  <input type="submit" name="submit1" value="a submit button">

</form>

The PHP script (checkout.php) that process the above form's action:

<?php var_dump($_POST); ?>

Test the above on your local machine by creating the two files in a folder named /tmp/test/ then running the built-in PHP web server from shell:

php -S localhost:3000 -t /tmp/test/

Open your browser at http://localhost:3000 and see for yourself.

One would wonder why would we need to submit a named button? It depends on the back-end script. For instance the WooCommerce WordPress plugin won't process a Checkout page posted unless the Place Order named button is submitted too. If you alter its type from submit to button then this button won't get submitted and thus the Checkout form would never get processed.

This is probably a small detail but you know, the devil is in the details.