When you want to choose what goes there
An automatic eraser decides for you what should fill a gap. Most of the time that is what you want. But sometimes you know better: the tiles should continue in the same pattern, the bricks should line up with their neighbours, the clean patch of wall two metres to the left is exactly what belongs here. That is what a clone stamp is for. You point at the source; the tool copies from it, at your brush, as you paint. Nothing is invented, so nothing can be wrong in a way you did not choose.
Clone or Heal
Clone copies the source pixels exactly, with a hard edge. It is right for patterns and anything with sharp structure, where blending would smear the lines — tiles, brickwork, fabric, text on a sign you are repeating. An optional 0–4 pixel feather softens only the very edge of the stroke, inside it, never outside.
Heal copies the same texture, then corrects it. It measures the colour difference between the source and the target on a ring of pixels just outside your stroke, and interpolates that difference smoothly across the stroke: at the edge it matches exactly, and inside it blends between the edge values. The result keeps the source's grain and detail but takes on the target's light and colour, so a patch taken from a sunlit part of a floor can cover a stain in a shaded part without showing a seam. It is the right choice for walls, floors, skies, paper and any surface whose brightness varies across the photo.
Aligned and non-aligned
With Aligned on, the offset between source and brush is fixed by your first stroke and kept for every stroke after it, so the source crosshair follows your brush and repeated strokes stay in register — exactly what you want for a pattern. With Aligned off, every new stroke starts copying from the source point again, which is better when you want to stamp the same clean patch over several separate marks. Changing the source resets the offset either way.
How it behaves
Before you paint, the brush shows a half-transparent preview of what it will copy, so you can line up a pattern before committing. While you paint, the pixels are copied from the photo as it was when the stroke began — so painting over the source area cannot copy your own fresh strokes back into themselves. When you lift, the stroke becomes one step in History, with its exact area recorded; Undo removes that stroke and nothing else, and the Restore brush can paint the original back over any part of it. Only pixels under your strokes are ever written.
When another tool is quicker
For a single object on a busy background, the automatic eraser is usually faster: Remove unwanted objects lets you click the object and rebuilds the area for you. For dust and specks, the one-click Blemish tool on Remove blemishes repairs each spot as you click. And if the eraser's result is close but borrowed the wrong texture, its Pick region source option lets you show it where to copy from — a clone stamp for the automatic eraser.
Not for faces or documents
Heal matches light and colour on surfaces; it is not a skin retouching tool, and this site does not offer face reshaping or beautification. It is also not for altering documents, IDs, stamps or signatures.