How AI Background Removal Works
What the AI engine actually does, why it downloads once, and where it struggles.
Background removal is segmentation: the AI engine looks at every pixel and decides whether it belongs to the subject or to the background, then keeps the subject and makes the rest transparent.
On this site the engine runs in your browser, not on a server. That is why it downloads once (about 40 MB) and is cached afterwards, and why your photo never leaves your device.
Clear subjects work best: a person or a product against a contrasting background. The engine struggles with the same things every remover struggles with — fine hair, fur, glass, smoke, shadows that blend into the background, and subjects whose colours match the background.
A transparent PNG is the honest output. JPEG has no transparency, so a JPEG "no background" result would silently add a white background. This tool therefore always downloads a PNG.
Always check the edges at full size before using the result, especially around hair. If the edges look rough, a clearer photo with better contrast will usually help more than running the tool twice.