This is normal and does not slow down your store or affect your customers. Kiwi Sizing is working correctly.
You may see warnings like "Unused JavaScript" or "Reduce JavaScript" in tools such as:
Google PageSpeed Insights
Lighthouse
GTmetrix
These warnings are expected for apps like Kiwi Sizing.
Why this appears
Kiwi Sizing includes small pieces of extra code to ensure the size chart works reliably across:
All Shopify themes
All devices (mobile, tablet, desktop)
All browsers
Speed tools flag this code even when it does not cause real-world performance issues.
This helps ensure your size chart displays correctly for every customer.
Will Kiwi Sizing slow down my store?
No. Kiwi Sizing does not cause a noticeable slowdown for your customers.
Kiwi Sizing is used by 30,000+ Shopify stores, and this code is part of a stable, production-tested version of the app.
Your size chart will load normally without affecting your store experience.
Will this hurt my PageSpeed score or SEO?
No. This does not negatively impact your SEO or search rankings.
These warnings are recommendations from testing tools, not errors.
Many Shopify apps and Shopify’s own features show similar warnings.
Do I need to fix anything?
No action is required. Kiwi Sizing is working as expected.
Your size chart will continue to display properly for your customers.