Inverting replaces every colour with its opposite: black becomes white, white becomes black, red becomes cyan, and every value in between is subtracted from its maximum. It is the digital equivalent of a photographic negative.
The most practical use is scanned film. If you have negatives from a family archive and have photographed or scanned them, inverting is the step that turns them back into viewable images. It also produces instant dark-mode versions of simple diagrams — a black-on-white flowchart becomes white-on-black in one pass — and it makes faint pencil or low-contrast detail dramatically easier to see.
The inversion runs locally on a canvas. Nothing about the image is uploaded.
Inverting a scanned colour negative gets you most of the way but not all of it. Colour film carries an orange base mask — a deliberate correction layer built into the emulsion — and inverting turns that into a strong blue cast across the whole frame. Correcting it properly means adjusting the colour balance afterwards in an image editor.
Black and white negatives have no mask, so inverting them is genuinely all you need. Follow with Brightness & Contrast if the result looks flat, which it often does because scanner software optimises exposure for the negative rather than for the positive you actually want.
Every channel value is replaced by 255 minus itself. Applying that twice returns the original number exactly, with no rounding and no drift. The only loss across a round trip comes from re-encoding a JPEG twice, and at quality 0.92 that is not visible.
This makes inversion safe to experiment with in a way most filters are not: if you do not like the result, invert again and you are exactly where you started.
Yes. Inversion is its own inverse — applying it a second time restores the original values exactly.
For black and white negatives, essentially yes. Colour negatives carry an orange base mask that becomes a strong blue cast when inverted, and correcting that needs colour balance adjustment in an image editor.
No. It is an exact arithmetic operation on each channel. The only change is the re-encoding step, done at quality 0.92 for JPEG.
For simple black-on-white line art, yes — it works well. For anything containing photographs or coloured branding, inverting looks wrong, since photos become negatives too.
Yes. Any number of images can be inverted in one run and the results are delivered as a ZIP.
No. The inversion happens on a canvas inside your browser.