Preconnect / Prefetch
Preconnect is a resource hint that tells the browser to establish a connection (DNS lookup, TCP handshake, TLS negotiation) to an external domain early — before that domain's resources are actually requested. Prefetch hints that a resource may be needed for future navigation.
Why It Matters for Shopify Stores
For Shopify stores using external CDNs, Google Fonts, or payment processors, preconnecting to these domains before they're needed can save 100–300ms per domain per page load. Adding <link rel='preconnect' href='https://fonts.googleapis.com'> eliminates connection delay when the browser later requests those fonts. This is a low-effort, high-impact optimization for stores with multiple third-party integrations.
How to Check Your Store
In Chrome DevTools Network tab, look for resources from external domains. Cross-reference with your theme's <head> section to see which domains have preconnect hints vs. which are loaded cold.
Use the free shopify speed test toolHow to Fix It
Add preconnect hints for frequently used external domains (Google Fonts, Shopify CDN, analytics endpoints) in your theme layout's <head> section. Use preload for the LCP image specifically.
Related Terms
TTFB (Time to First Byte)
Core Web VitalsTime to First Byte is the time between a user's browser making an HTTP request and receiving the first byte of data from the server.
FCP (First Contentful Paint)
Core Web VitalsFirst Contentful Paint marks the point when the browser first renders any text, image, or non-white content to the screen.
Render-Blocking Resources
PerformanceRender-blocking resources are CSS or JavaScript files that prevent a browser from displaying page content until they've fully downloaded and parsed.
Shopify CDN
ShopifyShopify's CDN (Content Delivery Network) automatically serves your store's images, JavaScript, and CSS from servers geographically close to your visitors.
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