BLACK & WHITE
☞ runs entirely in your browser — nothing is uploadedDrop your image here
or click to browse — JPG, PNG, WebP
Grayscale preview
OneImageTool
Free Image Tools
BLACK & WHITE
Upload a JPG, PNG or WebP and convert to black and white instantly with a live preview.
or click to browse — JPG, PNG, WebP
Grayscale preview
black and white
Every pixel collapses to one brightness value using the standard luminance weights — 0.299 red, 0.587 green, 0.114 blue. Those numbers are not arbitrary: they approximate how much each channel contributes to perceived brightness, which is why a red apple and a green leaf of the same measured intensity come out as different greys.
The naive alternative, averaging the three channels equally, is what makes amateur black-and-white conversions look flat — skies go too light, foliage too dark. This page uses the weighted version, the same one most desktop editors default to.
three steps
Choose a colour JPG, PNG or WebP. Nothing is sent anywhere, so the only size limit is the memory of the device you are on.
Conversion runs on the decoded pixels the moment the file loads. What you see is the actual output, not a CSS filter sitting over the original.
Save as PNG to keep the result lossless, or as JPG and WebP with a quality slider when it is going on a web page.
quick answers
Standard luminance weights, 0.299R + 0.587G + 0.114B, applied per pixel. It is the formula most editors use by default, so the result should match a plain desaturation in Photoshop or GIMP.
Visually the same for most images, and the adjust saturation tool at 0% gets you there too. This page is the one-click version with nothing to configure.
Usually a little, because the three colour channels now carry identical data and compress well. It is not a compression tool though — run the result through compress image if size is the goal.
Yes. Only the red, green and blue channels are touched, so a transparent PNG stays transparent as long as you export back to PNG.
Use adjust brightness for global exposure, or adjust highlights to pull back blown areas. Both accept the greyscale file you download here.
No. Conversion runs on a canvas in your browser, and the page keeps working with the network off.
Yes — free, no watermark, no sign-up.