Images are the heaviest elements on most Shopify stores. Optimizing them delivers the biggest speed improvements with the least effort.
Start with the Right Format
JPEG for photographs with many colors. PNG for images needing transparency. WebP for the best compression across all types. Shopify supports WebP natively.
Resize Before Uploading
Do not upload 4000px images when your theme displays them at 800px. Resize to the maximum display size. This alone can reduce file size by 80%.
Compression Tools
TinyPNG, Squoosh, and ImageOptim compress images without visible quality loss. For bulk work, use a Shopify image optimization app.
Image CDN
Shopify automatically serves images through Cloudflare's CDN. This is already optimized, but ensure your theme uses Shopify's image filters for responsive sizing.
Lazy Loading
Implement lazy loading so images load only when needed. This speeds up initial page load and saves bandwidth for visitors who do not scroll all the way.
Alt Text for SEO
Every image needs descriptive alt text. This helps Google understand your images and improves accessibility. Use keywords naturally.
Image optimization is the highest-impact, lowest-effort speed improvement you can make.