# Ecommerce Image and Video Performance > Make product images and videos faster while preserving the detail shoppers need to judge products confidently. - Type: Merchant guide - Level: Intermediate - Reading time: About 7 minutes - Audience: Written for store owners, builders, and designers refining high-performance ecommerce stores. - Last updated: 2026-11-04 - Canonical page: https://academy.getzenbasket.com/merchant-questions/ecommerce-image-and-video-performance/ - Part of: [Merchant Questions](https://academy.getzenbasket.com/merchant-questions/) on ZenBasket Academy --- ## What you need to know ### Why are product images slowing down my store? Product images slow a store when files contain more pixels or bytes than their displayed size needs, or when too many load immediately. Original photography files should be transformed into web-sized versions before delivery. ### What image format should ecommerce stores use? Use modern formats such as AVIF or WebP when they preserve the required product detail, and the customer's browser is supported, with an appropriate fallback. Choose the format by image type and measured quality, not by one universal rule. ### How large should ecommerce images be? An ecommerce image should be large enough for its maximum displayed size and zoom need, not for the camera's original resolution. Generate several widths, so a phone does not download the desktop or zoom file unnecessarily. ### What is responsive image delivery? Responsive image delivery gives the browser several image sizes or crops and lets it choose the one suited to the layout and screen. This reduces transfer while preserving sharpness on larger or high-density displays. ### What is image compression? Image compression reduces file size by storing image data more efficiently, sometimes by removing detail people are unlikely to notice. Compare the compressed result at the real display and zoom sizes before publishing it. ### What is lazy loading? Lazy loading delays an offscreen image, video, or frame until it is near the visible area. It prevents below-the-fold media from competing with the content a shopper needs first. ### Should every image be lazy loaded? No. Images visible on the first screen, especially the likely LCP image, should normally be discovered and loaded promptly. Lazy-load images farther down the page where delay will not leave the first view incomplete. ### Why shouldn't the main above-the-fold image always be lazy loaded? Lazy-loading the main above-the-fold image can delay its request until after the browser runs additional page logic. That can make the most important visual appear later and worsen LCP. ### How should product videos be optimized? Use a poster image, compressed web video formats, sensible dimensions and streaming or multiple quality levels when supported. Do not download or autoplay the full product video before the shopper shows intent unless its value clearly justifies the cost. ### How do I balance image quality and performance? Set a quality standard based on the product detail customers must inspect, then create the smallest file that meets it at each display size. Review returns and support questions, so compression does not hide color, texture, or label details. ### A quick store check List each above-the-fold image with its displayed dimensions, transferred size, format and loading priority; fix the largest mismatch first. --- ## Frequently asked questions ### Should every product image use the smallest possible file? No. Use the smallest file that still shows the product detail needed at its displayed size and supports customer confidence. ### Can a video thumbnail load before the video? Yes. A poster image can provide context while the heavier video waits for customer intent or an explicit play action. --- ## Related learning path - **Core Web Vitals for Ecommerce** - **Ecommerce JavaScript Performance** - [ZenBasket Build Guide](https://help.getzenbasket.com/zenbasket-builder/)