Start with the display requirement
A thumbnail and a zoomable product image serve different purposes. Very large source images can add unnecessary weight when shown small. Decide which details customers need to inspect before choosing export dimensions.
- List thumbnail and detail uses
- Check actual display dimensions
- Preserve important texture and labels
- Avoid uploading unnecessary originals
Compress with a visual check
Reduce file size gradually and compare the result at the intended display size. Aggressive compression can obscure colour boundaries or small print. A generic file compressor is not a substitute for checking the product's presentation.
- Keep a source original
- Compare quality at useful sizes
- Review supported image formats
- Check transparent backgrounds where needed
Retest the complete product page
Image improvements need to be tested alongside galleries, variant images and mobile layout. Measure under the same conditions as the baseline. An image-only fix may leave heavy scripts or slow interactions untouched.
- Check gallery and zoom behaviour
- Verify variant image changes
- Record before-and-after page measurements
- Review other performance findings
A common question
Is the smallest possible image always best?
No. The image still needs to show the details required for a confident purchase. Optimise for the displayed use and verify clarity.