GZIP / Brotli Compression
GZIP and Brotli are server-side compression algorithms that reduce the size of text-based web assets (HTML, CSS, JavaScript) before transmission to the browser. Brotli is newer and achieves 15–25% better compression than GZIP. Both are transparent to the user.
Why It Matters for Shopify Stores
Compression reduces the bytes transferred over the network, directly improving load times — especially on mobile connections. Shopify's servers apply compression automatically to all text assets served through its CDN. For merchants, this requires no action. However, custom HTML served outside Shopify's CDN (custom checkout pages, external landing pages) should verify compression is enabled.
How to Check Your Store
In Chrome DevTools Network tab, check the 'Content-Encoding' response header. It should show 'gzip' or 'br' (Brotli) for HTML, CSS, and JavaScript files. Shopify-served assets are always compressed.
Use the free shopify speed test toolHow to Fix It
N/A for standard Shopify stores — compression is handled automatically. For external pages or self-hosted assets, enable GZIP/Brotli on the server configuration.
Related Terms
Page Weight
PerformancePage weight is the total size of all resources required to load a web page — HTML, CSS, JavaScript, images, fonts, and other assets.
Content Delivery Network (CDN)
PerformanceA CDN is a geographically distributed network of servers that caches and serves web content from the server closest to each visitor.
Shopify CDN
ShopifyShopify's CDN (Content Delivery Network) automatically serves your store's images, JavaScript, and CSS from servers geographically close to your visitors.
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.
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