Performance

Browser Caching

Browser caching stores copies of web assets (images, CSS, JavaScript) on a visitor's device after their first visit, so subsequent page loads retrieve those assets from local storage rather than re-downloading them from the server. Cache duration is controlled by Cache-Control and Expires HTTP headers.

Why It Matters for Shopify Stores

For repeat Shopify store visitors, browser caching dramatically reduces load times on their second, third, and subsequent visits — the images and stylesheets are already on their device. Shopify's CDN sets appropriate cache headers for theme assets automatically. The most common issue is third-party scripts from apps that set short cache durations or no-cache headers, forcing re-downloads on every visit.

How to Check Your Store

In Chrome DevTools > Network tab, check the 'Cache-Control' response header on asset files. Shopify CDN assets typically show long cache durations. Note any assets with 'no-cache' or short max-age values.

Use the free shopify speed test tool

How to Fix It

N/A for Shopify CDN assets — Shopify manages caching. For custom scripts or external integrations, ensure they set appropriate Cache-Control headers. Avoid including dynamic timestamp parameters in asset URLs that prevent caching.

Related Terms

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