Grayscale online

Printing on a black-and-white printer, or matching a photo to a newspaper-style layout, needs a clean gray version. The slider also lets you stop partway for a faded, muted look, which a printer's gray setting cannot do.

Amount runs from 0 to 100 and starts at 100. At 100 every pixel turns gray, at 50 the color is half gone, and 0 leaves the photo unchanged. The preview follows the slider as you drag. The conversion uses the standard luminance weights of about 21% red, 72% green and 7% blue, so a green field stays brighter than a blue sky.

A gray version often looks flatter than the color one, because two different colors with the same brightness turn into the same gray. A red flower on green leaves can almost vanish. Raise the contrast afterwards with Contrast, or pick a photo where the subject is lighter or darker than its background. Transparent areas stay transparent.

Threshold gives pure black and white with no grays in between, which suits signatures and line art. Sepia Tone gives a warm brown version instead of neutral gray. Duotone maps the same brightness to two colors you choose, such as navy and gold. All three save a PNG, like Grayscale.