How to Improve Size Chart Page Load Speed on Shopify
< 30ms LCP impact. Lazy load, defer render, tiny bundle.
What Slows Down Size Chart Apps
Bundle size. Many apps ship 100KB+ JS. Tailor Size Guide ships under 8KB gzipped.
Render-blocking. Apps that mount on initial render block FCP. Tailor Size Guide defers mount until first interaction (button click).
Font loading. Web fonts inside size chart popups can block rendering. Tailor Size Guide inherits theme fonts — no extra requests.
Modal markup pre-rendering. Avoid pre-rendering hidden modal markup. Use lazy createElement on first open.
Verify the Impact
Run PageSpeed Insights against your product page before + after install. The delta is your app's true cost. Most apps add 200-300ms LCP. Tailor Size Guide should add < 30ms.
FAQs
Size chart apps slow pages?
Most yes, ~250ms.
Tailor Size Guide impact?
< 30ms LCP. Lazy + small bundle.
Performance-first sizing
Tailor Size Guide is built for Core Web Vitals, not against them.