Nick Verwymeren

<p>WooCommerce uses number inputs for the cart quantities by default, as most browsers now support <code><input type="number" /></code>.</p>
<p>However, you may want to have JavaScript powered inputs if you want greater control over appearance. Simply install and activate this plugin to do so.</p>
<p>It optionally includes a <a href="https://github.com/jonstipe/number-polyfill" rel="nofollow ugc">Number Polyfill</a>, which is a polyfill for implementing the HTML5 <code><input type="number"></code> element in browsers that do not currently support it.</p>
<p>To include this, add the following code to your theme’s <code>functions.php</code> file:</p>
<pre><code>add_action( 'wp_enqueue_scripts', 'wcqi_enqueue_polyfill' );
function wcqi_enqueue_polyfill() {
    wp_enqueue_script( 'wcqi-number-polyfill' );
}
</code></pre>


WooCommerce Quantity Increment

WooCommerce Quantity Increment adds JavaScript powered quantity buttons to your cart page.

WooCommerce Quantity Increment vs Flexible Quantity – Measurement Price Calculator for WooCommerce