SmartSize gives you several ways to place the size chart button on your product pages — from fully automatic to developer-level control. You'll find them all in Settings → Button size charts → Placement. Here's what each method does, from top to bottom:

With Automatic placement there is nothing to set up: SmartSize adds the button beside your size selector automatically, wherever it appears. New stores start on this method, so it's already working the moment a product is linked to a size chart.

On your storefront, the button appears right next to the size options — exactly where shoppers look when they're unsure which size to pick.

Prefer a button that's always within reach? Floating button keeps the size chart button visible as shoppers scroll through the page. Select the card and click Use this method — no theme changes needed.

The button stays anchored to the edge of the page while shoppers browse photos, details, and reviews, so the size chart is never more than one click away.

Want to decide exactly where the button sits? App block placement places the button anywhere in your product page layout using a Shopify app block. Select the card and click Show setup steps to open the guided setup.

The Drag & drop setup walks you through four quick steps. Step 1 checks that your theme supports app blocks — any Online Store 2.0 theme does.

Step 2 does the heavy lifting: click Open theme editor & add app block and Shopify's theme editor opens with the SmartSize size chart block already placed on your default product template. Adjust its position if you like, then click Save — the button only shows on your storefront after you save.

You can also add the block yourself, without the guided setup. In the theme editor, click Add block inside your product information section, open the Apps tab, and choose Size chart button by SmartSize.

Once added, it behaves like any other theme block: drag it up or down to change where the button appears on the page, then click Save.

Step 3 only matters if your store uses custom product templates besides the default one — add the size chart block to each of them manually via Go to theme editor. Most stores only use the default template, so you can usually tick the checkbox and move on.

Step 4 is the final check: open a product page on your live storefront and test the button the same way a real customer would — on desktop and on mobile. Keep in mind that the button only shows on products linked to an active size chart; a draft chart won't render it.

Variant labels anchors the button next to your variant picker by matching its option label text — for example "Size" or "Length". Enter one or more option names, and SmartSize attaches the button to the first matching label it finds on the page. It's a good fit for themes where automatic placement doesn't land in quite the right spot.

At the bottom of the page, Advanced options groups two methods for developers and custom integrations. Custom placement attaches the button to any element on the page using a CSS selector, and Custom integration lets you trigger the size chart from your own UI by calling the SmartSize API. Each card carries its own step-by-step instructions — click Show setup steps on the method you want and follow along.

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