Shop Pay is the more common of the two in our index: it runs on 328 websites against 169 for Google Pay, and 118 sites use both. Counts come from real scans, not vendor claims.
Google Pay is a digital wallet platform and online payment system developed by Google to power in-app and tap-to-pay purchases on mobile devices, enabling users to make payments with Android phones, tablets or watches.
Shop Pay is an accelerated checkout that lets customers save their email address, credit card, and shipping and billing information so they can complete their transaction faster the next time they are directed to the Shopify checkout.
118 sites run both Google Pay and Shop Pay. That is 70% of the sites using Google Pay, the smaller of the two.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.