Performance characteristics

How the cart drawer loads, what it fetches and when, and what affects its speed.

This article is a draft and may be incomplete or change before publishing.

How it loads

The cart drawer comes from the Oxify: Cart Upsell & Gift app embed, so its script and stylesheet are added to your storefront pages while the embed is on. The script is a JavaScript module (browsers fetch these without blocking the page from rendering), and the shared files it needs are preloaded. The drawer is a full interactive app rather than a tiny snippet, so it does add JavaScript to those pages.

On page load vs. when the cart opens

The drawer is not loaded on demand: it is set up when the page loads and stays hidden until it is opened.

On page load — It attaches to your theme's add-to-cart buttons and cart icon, and makes a few small requests, such as reading the cart to attach an analytics session ID. If you use rewards, free gifts or add-ons, it also looks up those products at this point.
When the drawer opens — It refreshes the cart and loads what the open drawer needs: upsell recommendations, empty-cart recommendations and free-gift choices.

Measuring the impact

Oxify's Analytics doesn't include page-speed metrics. To see what the drawer adds, test the same page with the app embed on and off (for example in a duplicate theme) using PageSpeed Insights or your browser's Lighthouse.

What can affect performance

Modules that are switched on — The drawer renders every active module, and rewards and add-ons look up their products. Disable the ones you don't use.
Image size — Cart images are requested at a reduced size by default (the most optimized Image Optimization setting). If you moved it toward Less Optimized, images load larger.
Custom HTML / CSS — Anything you add in Custom HTML & CSS is added to the drawer. Keep it small.
Your theme — The drawer runs inside your theme's pages, so a slow theme stays slow with or without it.

If pages feel slow

Move Image Optimization toward More Optimized (Home → Cart Drawer → Settings → Show Advance Settings), disable modules you don't use, and trim custom HTML and CSS. Compare with the embed off to confirm what is responsible. See Troubleshooting: Performance issues / slow cart open.