A short post that will hopefully be helpful to somebody – I’ve had to write this because Shopify have an annoying policy of closing old forum threads when it’d be more useful to keep them open and have them updated.
This thread;
Has an outdated solution for the problem.
Problem
If you enable the Ajax updating in the drawer / minicart in Shopify you can update the quantities of the individual items in the cart. But you may have a small cart total items icon in your link to that minicart – how to update that without a page refresh?

The Solution Part 1 – Collections page
If you have add to cart buttons on the collections page you need to modify the file assets/ajax-cart.js.liquid. Specifically the adjustCartCallback
method.
adjustCartCallback = function (cart) { // Update quantity and price updateCountPrice(cart); // This is the new line that updates the cart counter $('.cart-counter').html(cart.item_count); // Reprint cart on short timeout so you don't see the content being removed setTimeout(function() { isUpdating = false; ShopifyAPI.getCart(buildCart); }, 150) };
The Solution Part 2 – Product page
Assuming you’ve Ajaxified the product view page using this guide » , then you’d update the snippets/ajaxify-cart.liquid template and specifically the Ajax success callback;
$.getJSON(_config.shopifyAjaxCartURL, function (cart) { if (_config.cartCountSelector && $(_config.cartCountSelector).size()) { var value = $(_config.cartCountSelector).html() || '0'; $(_config.cartCountSelector).html(value.replace(/[0-9]+/, cart.item_count)).removeClass('hidden-count'); } $('.cart-counter').html(cart.item_count);