Use a format with alpha
PNG, WebP and still AVIF can represent transparent pixels. JPEG cannot, so transparent areas must be filled with a background colour when exporting JPG.
Review fine edges
Hair, motion blur, glass and semi-transparent materials are difficult for segmentation models. Inspect the result against both light and dark backgrounds before use.
Know the model scope
FreeImageKit's beta remover is a person/selfie segmenter. It is not represented as a general product, animal or object cutout model.
Try the related local tools
This guide describes format behaviour and product capability, not a guarantee for every source image or third-party workflow. Keep your original files and verify important exports.