pngtoolskit.org
PNG and image utilities, in the browser
Say hi →

Convert a PNG to Grayscale

perceptually-weighted luma · batch · keeps transparency · nothing uploaded

Turn a colour image black-and-white — a true grayscale conversion, not a washed-out desaturation. Drop one file or a batch; it runs in your browser with no upload, and any transparency is preserved. The result is a neutral gray PNG that prints and reproduces cleanly.

Drop images here

Multiple files allowed

    no files
    Ready.

    Why it looks right, not muddy

    A naïve grayscale just averages red, green and blue — which makes reds too dark and greens too light, because your eye doesn't weight the channels equally. This tool uses the standard luma formula (about 30% red, 59% green, 11% blue), so brightness matches how a scene actually looks to a human. That's the same weighting film and broadcast use.

    Common uses

    FAQ

    How do I make an image black and white?

    Drop it above and click Convert — the grayscale version appears with a Download link, processed entirely in your browser.

    Is this the same as desaturating?

    The result looks similar but the method matters: this uses perceptual luma weighting, which keeps relative brightness accurate. A flat average or a naïve desaturate can leave reds and greens looking wrong.

    Does it keep transparency?

    Yes — only the colours are changed; the alpha channel is untouched, so transparent areas stay transparent.