BigCommerce Image Optimization: Dimensions, Compression & Best Practices

Laura Cummins

Dec 22, 2025 5 min read

Updated Dec 22, 2025

BigCommerce handles image delivery differently from most ecommerce platforms. Every uploaded image passes through Akamai's CDN, which re-encodes files at its own quality settings before serving them to shoppers. This means your compression strategy needs to account for two rounds of processing -- yours and the CDN's.

What Size Images Does BigCommerce Need?

On BigCommerce, product images display at 1280x1280 pixels on the storefront, but the zoom feature pulls from the original upload. Images under 2048px on either dimension produce visible pixelation when shoppers click to zoom, which reduces buyer confidence and conversion rates.

BigCommerce supports up to 8MB per file, but there is no performance benefit to uploading images that large. According to BigCommerce product image documentation, the platform automatically generates multiple sizes from your upload, so starting with a well-compressed source at the right dimensions produces the best results across all display contexts.

The Double-Compression Problem

BigCommerce's Akamai CDN re-encodes every image it serves, regardless of the compression you applied before uploading. If you upload a JPG already compressed to quality 70, the CDN applies another round at approximately quality 80. The result is cumulative quality loss -- similar to making a photocopy of a photocopy.

The solution: upload images compressed to quality 85-90, not 70-75. This gives the CDN room to apply its compression while keeping the final output sharp. A product photo uploaded at quality 85 and 400KB typically exits the CDN at around 300KB with no visible degradation.

Preparing Photos for Upload

1. Upload images at 2048x2048 for zoom support. BigCommerce product zoom requires images at least 2048x2048 pixels. Anything smaller causes visible pixelation when shoppers click to zoom. Upload at this resolution even though the storefront displays at 1280x1280.
2. Compress before upload to counter CDN re-encoding. Run product photos through a browser-based compressor at quality 85-90. Starting from a compressed source ensures the CDN output stays sharp. Aim for files under 500KB.
3. Use JPG for photographs and PNG for graphics with transparency. BigCommerce CDN handles both formats well. Avoid uploading WebP directly since older Stencil themes may not render it. Let the CDN handle format conversion to WebP for supported browsers.
4. Verify images after bulk CSV import. When importing products via CSV, check that all image URLs resolve and return 200 status codes. BigCommerce skips images that return 404 or redirect, leaving product listings without photos.

Stencil vs Blueprint Theme Differences

How do BigCommerce themes differ? Stencil themes use responsive image loading with automatic size selection, while Blueprint themes serve fixed-size images. Migrating from Blueprint to Stencil requires re-uploading product images at 2048x2048 to take advantage of the zoom feature -- Blueprint-era images at 1024px will look blurry in the new theme.

For a comparison of modern image formats that BigCommerce can serve through its CDN, see our AVIF vs WebP comparison. For general ecommerce image compression techniques, check our guide to bulk compressing product photos and the LighterImage insights hub.