The best Shopify size finder apps, compared (2026)

"Sizing app" covers three different products: size chart apps that display measurements, size finders that quiz the shopper, and fit engines that recommend per garment with a confidence score. They differ in price by an order of magnitude because they do different amounts of the work.

The five, ranked

1. Garu — garment-specific fit engine with try-on attached, from $199/mo (free tier)
2. Kiwi Size Chart & Recommender — the category incumbent, 4.8 stars across ~1,100 reviews, free to $26.99/mo
3. Smart Size Chart & Fit Finder — quiz-based size finder, flat pricing
4. MP Size Chart & Size Guide — budget charts with AI-assisted recommendations
5. True Fit / Fit Analytics — enterprise fit platforms, custom-priced

Roughly 42% of fashion returns are size-related; charts organise information, finders answer, fit engines answer per garment and show it on the shopper. The full guide includes a decision framework by generation.

Companion guide: the best Shopify virtual try-on apps · How Garu's AI sizing works