Will virtual try-on slow down my Shopify store?

Theme app extensions do not touch your theme code

Older Shopify apps injected scripts by editing theme.liquid, and the injected code often stayed behind after uninstall, quietly loading on every page. Looksy installs as a theme app extension instead: you add the block through the theme editor, Shopify controls how it loads, and no line of your theme's code is edited. Uninstalling removes it cleanly — no orphaned script tags to hunt down later. That does not make any app weightless, but it removes the most common way apps have historically damaged store speed: leftover code the merchant never knew was there.

The AI runs when a shopper starts a try-on, not on page load

Generating a try-on image is heavy work, but it is not work your product page does. The shopper uploads a photo, the image is generated off the page, and the result comes back to the browser — the same request-and-response pattern as any upload. Shoppers who never tap the try-on button trigger none of it. So the question that matters for your speed score is not how demanding the AI is, but what the block itself adds to the page — and that is something you can measure on your own store rather than take on trust.

Measure it before and after, on your own store

Looksy publishes no speed benchmarks, and you should not trust any app's own numbers anyway — themes, image sizes and other apps make every store different. The honest method is a before-and-after test. Before installing, record your product page's scores in Shopify's web performance report in admin, and run the same page through PageSpeed Insights. Install Looksy on the Free plan, add the block, and repeat the same measurements on the same page. Compare. If the difference is unacceptable to you, uninstall — the theme app extension removes cleanly, so the test costs nothing but time.

Realtime video is the one mode that works the device harder

Photo try-on asks almost nothing of the shopper's device — one upload, one result. Realtime video try-on, available on the Scale plan, is different: it uses the live camera and updates continuously, which works the shopper's phone or laptop the way a video call does. Even then, that work happens in the session of the shopper who chose to start it; whether the feature adds anything measurable for shoppers who never touch it is exactly what the before-and-after test above will tell you. If your store runs photo mode only — realtime video exists only on the Scale plan — this concern does not apply to you.

Sources: the public Shopify App Store listing for Looksy. Last checked 27 July 2026.

Related questions: Do try-on apps need a developer to install? · Can I test try-on on a development store? · Can try-on appear outside product pages?