What fails on this store, and what needs a person.
Paste any Shopify storefront. It loads in a real browser and is tested against WCAG 2.2 AA, the standard behind the EAA, the BFSG and the ADA. You get the failing elements, not a score.
One page, about half a minute. Nothing is installed and no address is asked for.
What this does not tell you
It checks one page, and it checks only the criteria a machine can check. Whether your alt text actually describes the image, or whether checkout can be completed without a mouse, needs a person, and the results say which findings are in that group rather than counting them as passes. No tool can make a store compliant, and any that says otherwise is the one to walk away from.
Why the app exists, if this is free
Because a clean page does not stay clean. A theme update, a new app embed, or one edited section can break a page that passed last week, and nobody looks again until a customer complains. The app checks your home page, a collection page, a product page and your cart on a schedule, and emails you when something that was passing starts failing. This page is the one time check.