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Integration with non-Shopify platforms: Size Models
Integration with non-Shopify platforms: Size Models

This document explains how Size Models can be added as a custom attribute and used in size recommendations

Updated over a week ago

"Size Models" is one of the early steps of the Easysize/Fit Quiz integration on non-Shopify shops. This article will explain what size models are, why Fit Quiz doesn't require size charts, and how to create the unique size and fit recommendation logic for your brand.

See the step-by-step guide on integration with non-Shopify platforms here.

What are Size Models?

Size models are a special setting indicating whether selected items have a particular fitting to them. For example, an oversized item, or an item that is running slightly smaller. You can create as many or as few size models as you wish and use our default or your custom models.

The Fit Quiz algorithm uses these size models, along with your existing order and return data, to determine the unique style, size, and fitting factors of your items. This eliminates the need for size charts or garment measurements.

Want to learn more about our algorithm and how it recommends sizes? Check this article for more details.

Adding size charts or measurements

A common question among shops is where and how to add their size charts and measurements. The good news is that Fit Quiz doesn’t require any size charts or measurements, so there's no need to prepare or share these. Instead Fit Quiz uses your size models, which you can assign to products on the “Mapping” table and indicate their unique size and fit settings.

Default Size Models

Default Size Models cover the most frequently used size and fit patterns based on our close work with hundreds of fashion brands globally.

These models include:




True to size


For products that generally fit as expected

One size up


For products that run smaller, customers should consider buying one size larger

One size down


For products that run larger, customers should consider buying one size smaller

Half size up


For products with a slightly smaller fit, suggesting customers buy half-size larger

Half size down


For products with a slightly larger fit, suggesting customers buy half-size smaller

Custom Size Models

In addition to default models, you can create Custom Size Models. These are perfect for products with special and unique sizing.

There's no limit to how many custom models you can create, and Fit Quiz can provide recommendations at the product level. This means each product or collection can have its unique size model if necessary.

Example of Custom Size Models: 




Slightly small


Products are running slightly slimmer. Customers are suggested to buy 0.5-1 size larger

Slightly oversized


Products are running slightly oversized. Customers are suggested to be 1-1.5 sizes smaller

For Custom Size Models to work as expected, please share a table similar to the example above with all the details with us

Implementing Size Models

Size Models are implemented within the JS library:

  • add the conf object

  • within the conf object locate product_model attribute – the size model shall be added and passed in this attribute

Check our developer docs for more information here.

Alternative No-Tech implementation of Size Models

If you don't have tech resources to implement Size Models as described above (in the JS library), please reach out to us. We have alternative ways of gathering sizing and fitting information about your brand, that don't require technical assistance from your side. 

→ Next steps

Congratulations – you've just completed the second step of integrating Easysize/Fit Quiz on your e-commerce platform. Here's what you should do next:

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