Choose image formats by visual quality, transfer size and delivery support. Keep original photographs so future exports do not compound compression damage.
Compare the actual subject
Export the same photograph at its intended display size in candidate formats. Inspect text on products, fine PCB traces, gradients and shadows. The smallest file is not useful if customers cannot see the detail needed to understand the product.
Deliver with appropriate fallbacks
A picture element can offer alternative formats while keeping an image fallback. Check the browsers your audience uses and the image pipeline supported by hosting. Format conversion should accompany resizing; a huge modern-format image can still waste bandwidth.
Verify publication outputs
Inspect the files requested by a real mobile browser rather than assuming the CMS delivered the optimised version. Keep meaningful alt text and dimensions. Document export settings so future uploads receive the same visual review and size checks.