If a SmartSize button isn't appearing on a product page, it's almost always one of six quick checks. The missing button may be the Size Chart button (from a size chart), the Find my size button (from a fit quiz), or both — the checks below cover every case. Work through them in order.
💡 Before you start: always test on your live storefront, not the theme editor preview, and refresh the product page after each change.
1. Check the app extension is active
The Size chart extension and the Fit quiz extension are separate — each one powers its own button. Open the SmartSize Home page and look at the App extensions card. If the extension you need shows Inactive, turn it on in your live Shopify theme and save.
Once saved, the card shows Active for each extension you turned on.
2. Check the chart or quiz is Active
A size chart or fit quiz in Draft is hidden from shoppers, even when everything else is set up correctly. Open Size charts or Fit quizzes, select the one that should appear, set its Status to Active, and save.
3. Check the product matches the display rules
Charts and quizzes only appear on products that match their Product display rules. Open the chart or quiz and confirm your test product appears in the matching products list.
If the product is missing, update the rules. For a quick test, select the exact product you're checking so there's no doubt it matches.
4. Check your plan includes fit quizzes
This check only applies to the Find my size button. Fit quizzes are available on the Pro plan — on Free, Starter, or Growth the button won't appear even when everything else is configured. You can review your current plan under Plans.
5. Check button placement after a theme change
If you recently switched or updated your theme, automatic placement may no longer find the button's spot. SmartSize shows a warning under Global settings → Button placement when this happens.
If you see this warning, switch to the Floating button or App block placement — both work independently of your theme's structure.
6. Check you saved the live theme
App extensions are enabled per theme. If you turned the extension on in a draft or development theme, shoppers on your live theme still won't see the button. Enable it on the theme that is currently published, then save.
Quick reference
The most common causes at a glance:
Cause | What happens | Fix |
App extension is inactive | Shopify doesn't load the button | Turn the extension on in your live theme |
Chart or quiz is in Draft | Hidden from shoppers | Set the status to Active and save |
Product doesn't match the display rules | Button only appears on matching products | Add the product to the display rules |
Theme change broke automatic placement | The button's spot no longer exists | Switch to Floating button or App block |
Only one extension is activated | The other button stays hidden | Activate both extensions if you use both products |
Saved on a draft theme | The live theme is unchanged | Enable the extension on the published theme |
Changes not saved | The storefront shows the old setup | Save in SmartSize or Shopify, then refresh |
Plan doesn't include fit quizzes | Find my size never appears | Upgrade to the Pro plan |
Still not working?
Send us a message and include:
the product URL where the button is missing
the name of the size chart or fit quiz that should appear
a screenshot of the App extensions card
a screenshot of the product display rules
your Shopify theme name
This helps us quickly see whether the issue is setup, product matching, or the theme structure.
💡 Tip: testing with a single exact product selected in the display rules is the fastest way to rule out matching issues.