When the Result Comes Out Wrong

There is a hole in the middle of the subject

The model has decided that part of your subject is background. This nearly always happens for one of three reasons: the area is reflective and is showing you the actual background, it is transparent and the background is genuinely visible through it, or it is a region whose colour closely matches the background.

Reflective surfaces — steel bottles, glossy packaging, screens, metal jewellery — mirror the room. The model sees the room and removes it, which can punch a hole through the centre of an object. The fix is at capture: diffuse your light through a sheet of white paper or thin fabric so the reflections become soft and featureless rather than sharp images of the room.

Transparent objects have no single right answer. Whether background should show through a glass bottle depends on what you are using the image for, and the model will usually clear the inside along with the surroundings. If you wanted the interior kept, you cannot recover it by erasing more — you would need a photo against a plain surface, used uncut.

Colour matching is the easiest to diagnose: if the missing region is roughly the same shade as the background you shot against, that is the cause, and only a different backdrop will fix it.

There is a faint outline of the old background

This is fringing, and it is the most common complaint. The edge pixels of the subject contain a blend of subject colour and old background colour, so when you place the cut-out on a new colour the old one comes with it as a thin halo.

The quick fix is a careful pass around the outline with the manual eraser at a small brush size — 10 to 20 pixels. Work on the background side of the edge, erasing what remains next to the subject rather than trimming the subject itself. Undo and Redo are both available, so it is safe to work fast and step back.

The better fix is compositing onto a background closer in tone to the one you shot against. A subject photographed on light grey looks flawless on light grey and shows every imperfection on black. If you have any choice about the destination background, this costs nothing and works better than any amount of erasing.

If you cannot see the fringe, check on a strongly contrasting colour before you decide it is not there. It is invisible on the chequerboard transparency preview and obvious on a saturated colour.

Parts of the outline have been cut away

Notches taken out of a smooth edge, a thinned hairline, a missing strap or handle. The model has been too aggressive, usually because that part of the subject was in shadow, was very thin, or was low contrast against the background.

Shadowed edges are the usual culprit — an unlit jaw, the dark side of an object lit from one side. The model cannot distinguish dark subject from dark background. Lighting the subject from two sides, or simply moving it toward a window, removes the ambiguity at source.

Thin features like straps, wires, and stems are lost when they are only a couple of pixels wide. The answer is resolution: shoot closer or at a higher setting so those features occupy enough pixels to survive.

Nothing in the editing step can restore a cut-away edge — a manual eraser only removes more. If the silhouette is damaged in a way that shows at the size you will use, reshooting is the only real fix.

Background is left behind in gaps and holes

The space under a handle, between an arm and a body, inside the loop of a pair of scissors, between chair legs. These enclosed regions are surrounded by subject, and models frequently treat them as part of it.

This is the easiest failure to repair and the most obvious if you miss it. Zoom in, take the manual eraser at a medium brush size, and clear the enclosed area. It takes seconds.

Make a habit of checking specifically for it, because it is easy to overlook on the transparency preview — a leftover grey patch inside a handle can read as part of the object until you place the image on a coloured background and it turns into an obvious block.

The model will not load, or processing fails

The AI model downloads once on first use and then runs locally. That first download needs a working connection, and if it is interrupted you will see a message about the connection being reset. Reconnect and try again; the download resumes from scratch but the file is cached afterwards, so this only happens once per browser.

A very restrictive network — some corporate or school connections — can block the download entirely. If it consistently fails on one network and works on another, that is what is happening, and there is nothing to fix on this end.

An unsupported file produces a format error. JPEG, PNG, WebP and GIF all work. HEIC, the default on many iPhones, does not: share or export the photo as JPEG first, which iOS offers in the share sheet.

There is no file size limit, but very large images take proportionally longer and use more memory. If a huge image fails on a phone, the phone has run out of memory rather than the tool rejecting it. Resizing the photo to a few thousand pixels on its long side solves it and costs nothing you will see.

It looks worse than the original

Sometimes the honest answer is that this image should not have its background removed. Soft-edged subjects — knitwear, fur trim, feathers, hair in motion — genuinely do not have a findable boundary, and a cut-out will look harsher than the untouched photo.

Small or blurry originals have the same problem for a different reason: there is not enough edge information for the model or for you. Removing the background takes away the context that was hiding the softness, so the flaws become more visible, not less.

In both cases the alternative is a photo on a clean, plain surface, used as it is. A well-shot photo on a plain backdrop beats a poor cut-out in every setting, and takes less time.

Before deciding a result is bad, view it at the size it will actually be used. Judging a cut-out at 400% zoom is how most people conclude a perfectly usable image has failed.

A short diagnostic checklist

Was the subject clearly separated from the background by colour and brightness? If not, that is the cause of most problems in this list, and no editing will substitute for a different backdrop.

Was the subject far enough from the background that its own shadow did not land right behind it? Attached shadows are the most common source of ragged edges.

Was the original large and sharp? Thin features and fine edges need pixels to survive.

Have you judged the result on a colour that differs from the original background, at the size you will actually use? Most complaints resolve into either an invisible problem or a problem that only reshooting fixes.