Recommend the perfect size in seconds
A “Find My Size” button on every product page opens an AI size recommender that gives each shopper one answer — “Your size is M” — in seconds, and remembers it across visits and products. Available on SmartSize Pro plans.
From size chart to a single, personal answer
A size chart shows shoppers the measurements. The SmartSize fit quiz tells them their size. A Find My Size button opens a short quiz, and an AI size recommender matches the shopper to the best size in your chart — in under 30 seconds. It is transparent, not a black box: shoppers see exactly how each size fits every measurement before they add to cart.
Built for Shopify — find SmartSize on the Shopify App Store
SmartSize earned Shopify's Built for Shopify badge — the top-tier quality recognition for apps that meet the highest bar on storefront and admin performance, integration, and merchant experience. The “Find My Size” quiz is fast on mobile, light on your theme, and installs straight from the Shopify App Store.
Size charts from main dropshipping and print on demand brands
Printful
Printify
Gelato
Spocket
SheIn
Zendrop
DS
Printful
Printify
Gelato
Spocket
SheIn
Zendrop
DS
How the AI size quiz works
From first question to recommended size in under 30 seconds.
Shopper taps Find My Size
A button next to the size selector opens the quiz on any product — no app to download, nothing to set up for the shopper.
A few questions — or exact measurements
Prediction estimates measurements from a handful of simple questions; Precision uses real numbers. Shoppers can review and adjust before they see a result.
One clear answer, remembered
“Your size is M,” with a fit breakdown for every size. SmartSize remembers it and remaps it to other products — so they never retake the quiz.
Recommendations that remember the shopper
Take the quiz once and you're done. SmartSize reuses each shopper's measurements across visits and across your whole catalog — so the size is just there, every time.
- Shoppers never repeat the quiz — their size shows instantly on return visits
- On a different product, their measurements remap to that product's chart automatically
- A smoother repeat journey, with unlimited repeat recommendations per shopper
Validate recommendations before you publish
Simulate any shopper's measurements and see exactly why each size is recommended — or rejected — before a single change reaches your storefront. Smart defaults work out of the box; Fit Lab is there when you want more control.
A size quiz built for real catalogs
Upload your size chart and SmartSize does the rest — tailored flows, transparent recommendations, and tools to test before you launch.
Tailored to every catalog
Whether you sell hoodies, dresses, jeans, lingerie, or pet harnesses, SmartSize gives each category its own quiz flow with the right body parts and prompts — so the questions always make sense to the shopper.
- Men's / women's / kids' and unisex apparel
- Lingerie quizzes with bra-and-underwear-specific UX
- Pet quizzes for collars / harnesses and apparel
- Per-garment fit tuning — ease and fabric stretch
- Multi-language quiz flows out of the box
On brand, in every language
The quiz should feel like part of your store, not a bolt-on. Match it to your theme and let every shopper take it in their own language.
- Match the quiz to your brand's accent color
- Choose where the Find My Size button appears
- Personalize the button's icon / color and label
- Multi-language quiz flows shipped and maintained by SmartSize
- A dedicated mobile layout built for how shoppers buy
Smart, transparent recommendations
Three quiz types so every store finds the right fit for its catalog — and a result screen that shows shoppers exactly why a size was chosen. No black box.
- Prediction / Precision / Lingerie quiz types
- Optional measurement review step before the result
- Per-measurement fit visualization on the result screen
- Forgiving of looseness over tightness for real-world fit
- Balanced / Always-recommend / Strict matching modes
Fast and lightweight
The quiz is optimized for speed and loads without blocking your storefront — so the shopper experience stays smooth on every device.
- No impact on your store's loading times
- Quick and hassle-free install and uninstall
- Fully responsive across all devices
- Ultra-fast interface for effortless quiz setup
Three quiz types, one for every store
Pick the flow that fits your catalog — or offer the one your shoppers will actually finish.
No tape measure needed
A few simple questions — height, weight, age and body shape — and an AI model trained on real body data estimates the shopper's measurements. Fastest and lowest-friction; ideal for men's, women's and unisex apparel.
Exact measurements, maximum accuracy
The shopper enters their real measurements with step-by-step guidance. No estimation involved — the most accurate method, and the right choice for fitted, tailored or technical products.
Built for bras and underwear
A precision-style flow with imagery and prompts specific to lingerie — bust, underbust, waist and hip — so shoppers get a confident size for the hardest category to fit online.
Fit confidence, fewer returns
The wrong size is the number-one reason fashion gets returned. When every shopper gets a size recommendation they trust — and can see how it fits before they buy — they order with confidence and send less back, lifting conversion and protecting your margin.
The quiz rides on top of beautiful size charts.
Every plan starts with SmartSize's size charts — modern, mobile-friendly, multi-language, and built into the same app. The quiz extends them with a single, personal answer.
Explore size chartsSize quiz FAQs
What merchants ask before adding the SmartSize fit quiz.
What is a Shopify fit quiz?
How does the AI size recommender work?
Do shoppers need a tape measure?
Does the quiz remember a shopper's size across products?
Which products and categories does the quiz support?
Which plan includes the size quiz?
Loved by thousands of Shopify brands worldwide
Fewer returns. More profit. Less hassle.
SunDaze Surf
Netherlands
I love using this app! It's great. My customers love it. I've used a few different apps like this and this is the one I decided to stick with. It works well and has everything I need. The app developers are super lovely and helped me out when I needed help with a setting that I missed while setting up. They are also super happy to receive any feedback to make the app even better, which I always appreciate. Highly recommend!
Lifestyle Travel Trading
Australia
I just started using this App. Until now I have been copying size charts from the supplier and loading as images. It is not as professional as I wanted. Smart Size Charts offers so much functionality to standardise, create individual charts for one or more products and to manage the info to sort your brand. I had one issue with edging on a chart. I mentioned it to support. Helen asked me to give her access and added some CSS code and all was perfect. Loving the App so far and really making my site look so much more professional after spending time to upgrade everything. If you are looking for a great size chart App. This is it!
Moke Apparel
New Zealand
Smart Size Chart & Size Guide has been a real game changer for our business. The process to setup charts + guides was not only extremely easy but looked absolutely amazing. The ability to change between in/cm, add measuring notes + images and the ability to clone size guides made it a very fast and accurate way to display information. Our questions were answered promptly and the team was willing to assist not matter the question. You won't regret using this APP!
LePantalon
France
I've been using SmartSize - Size Guide for a few weeks now, and I'm really impressed! It's made a huge difference for our customers by providing them with a clear and accurate size guide. This has helped reduce sizing mistakes and made our customers much happier overall.Thank you!
HTO Apparel
United States
This is the only app that allows unlimited size charts. I love how customizable the size chart are and easily to be setup. Support is really helpful as well.
SassynTall
Canada
As a new business Smart Size has been so valuable to my store. The free plan has been such a great way to assist in saving money and allowing me to grow. I'll definitely upgrade when my store is getting regular sales.
Riversun
Israel
Great App , use it from the launch start and its always upgraded since , great communication with costumer service and future improves...
Bgo & Me
Spain
La mejor app para guía de tallas. Traducida a la perfección, super fácil de integrar. Lo mejor de todo, el servicio de atención al cliente. Son rapidísimos y súper amables. Totalmente recomendable y feliz de haberlos encontrado.
Bit of Cats
Germany
The size charts are really easy to add to the store and they look super nice. I had an issue with the theme font option not showing for me, and Helen was amazing. I think this is one of the fastest and friendliest support experiences I've had. Thank you!
SunDaze Surf
Netherlands
I love using this app! It's great. My customers love it. I've used a few different apps like this and this is the one I decided to stick with. It works well and has everything I need. The app developers are super lovely and helped me out when I needed help with a setting that I missed while setting up. They are also super happy to receive any feedback to make the app even better, which I always appreciate. Highly recommend!
Lifestyle Travel Trading
Australia
I just started using this App. Until now I have been copying size charts from the supplier and loading as images. It is not as professional as I wanted. Smart Size Charts offers so much functionality to standardise, create individual charts for one or more products and to manage the info to sort your brand. I had one issue with edging on a chart. I mentioned it to support. Helen asked me to give her access and added some CSS code and all was perfect. Loving the App so far and really making my site look so much more professional after spending time to upgrade everything. If you are looking for a great size chart App. This is it!
Moke Apparel
New Zealand
Smart Size Chart & Size Guide has been a real game changer for our business. The process to setup charts + guides was not only extremely easy but looked absolutely amazing. The ability to change between in/cm, add measuring notes + images and the ability to clone size guides made it a very fast and accurate way to display information. Our questions were answered promptly and the team was willing to assist not matter the question. You won't regret using this APP!
LePantalon
France
I've been using SmartSize - Size Guide for a few weeks now, and I'm really impressed! It's made a huge difference for our customers by providing them with a clear and accurate size guide. This has helped reduce sizing mistakes and made our customers much happier overall.Thank you!
HTO Apparel
United States
This is the only app that allows unlimited size charts. I love how customizable the size chart are and easily to be setup. Support is really helpful as well.
SassynTall
Canada
As a new business Smart Size has been so valuable to my store. The free plan has been such a great way to assist in saving money and allowing me to grow. I'll definitely upgrade when my store is getting regular sales.
Riversun
Israel
Great App , use it from the launch start and its always upgraded since , great communication with costumer service and future improves...
Bgo & Me
Spain
La mejor app para guía de tallas. Traducida a la perfección, super fácil de integrar. Lo mejor de todo, el servicio de atención al cliente. Son rapidísimos y súper amables. Totalmente recomendable y feliz de haberlos encontrado.
Bit of Cats
Germany
The size charts are really easy to add to the store and they look super nice. I had an issue with the theme font option not showing for me, and Helen was amazing. I think this is one of the fastest and friendliest support experiences I've had. Thank you!