Make the background transparent

How to get the best result

This tool works great when the background is a solid color clearly different from the subject: for example a logo on a white background, or a photo on a green/blue backdrop. Tap the background to pick its color, then adjust the tolerance to include more shades and soften edges to make the outline smoother and more natural.

When it's not enough

If the background has many colors or details (a complex real photo), color-based removal isn't enough: in those cases you need an AI tool that recognizes the subject.

Why colour keying works on logos and not on photographs

The method picks a colour and makes transparent the background that touches the edges, that is what resembles it and can be reached from the border of the image without crossing the subject. On a black logo on white, or on a product photographed against a neutral background, the separation is clean and the result is tidy. The white of an eye or of a shirt, closed inside the outline, stays where it is; an enclosed area that is background instead, like the inside of an «O», goes when you tap it, or with the box that removes that colour everywhere. On a real photograph the background colour often reaches the subject without a sharp outline, in hair or in a reflection, and there the cut-out punches holes.

Then there is a case that looks easy and is not: the almost uniform background, that is a white wall badly lit. To the eye it is all white, to the numbers it is a gradient of dozens of shades, and the tolerance that removes the dark corner starts eating into the subject.

Tolerance, and how to set it

A low value removes only the exact colour, and a halo of the old colour stays around the edges. A high value cleans the edges better but starts punching through the subject where colours resemble each other. The right point is almost always just before the subject starts losing pieces.

The check that matters is done on a dark background, not on the chequerboard: pale halos, invisible against white, jump out immediately. It is why a cut-out logo that looks perfect in one program shows a grey frame once placed on a black slide.

Hair, fur and semi-transparent things

These are the case where no colour keying works, and it is not a limitation of the tool: at the edge of hair every pixel is partly background and partly subject, and a method that decides yes or no cannot represent that. The result is the silhouette with a pudding-bowl haircut.

The same goes for glass, smoke, veils, insect wings and soft shadows. Those cases need tools that assign gradual transparency pixel by pixel, and the best ones today use trained models. When a photo has windblown hair against a complicated background, it is better to know beforehand than to lose an hour.

Saving without losing what you did

The format has to support transparency: PNG is the safe choice, WebP weighs less but is not accepted by every form. Saving as JPEG undoes all the work, because transparency becomes white or black, and it is the mistake discovered only once the image has been sent.

A second useful check is size: a PNG of a photograph is enormous, and if the cut-out subject is going on a web page it is better to reduce its dimensions first. PNG does not compress «by quality» the way JPEG does: the only lever is the number of pixels. Here the PNG comes out at most 1,600 pixels on the long side: a bigger photo is shrunk, and the page says so.

Nearby tools

For a round portrait there is Round photo, for format Convert image and for size Compress image. To add lettering on top Write on a photo, and for a signature on a transparent background Online signature.