Convert Image to Black and White
Greyscale weighted for how bright the eye finds each colour, not averaged. Averaging flattens a red-on-blue logo into one rectangle.
How it works
Open the image
Full resolution, in this tab.
Choose the strength
All the way for black and white, part way to drain some of the colour.
Download
A PNG at the original pixel size.
Convert an image to black and white, grey or pure B&W
Two ways to turn an image to black and white. Greyscale keeps every shade, weighted for how bright the eye finds each colour. Pure black and white makes every pixel black or white: image to pure black and white online, image to black and white no grey, for stencils, laser engraving, printing and scanning.
Convert image to black and white pdf: set Save as to PDF. A pure black-and-white PDF is stored as 1-bit, so edges stay crisp and no grey creeps in. Image to black and white high quality keeps the original resolution.
For a picture to black and white drawing or image to black and white clipart, use pure mode with the threshold picked automatically; turn on dithering for a photo to keep its shading as dots. It is image to black and white online free, with no image to black and white app to install.
Why it matters
Weighted the way the eye sees
Rec. 709 weights: green counts for most of perceived brightness, blue for least. An averaged conversion makes red and blue land on the same mid-grey, so a red logo on a blue field becomes one flat rectangle.
Partial conversion
Strength below 100% leaves some colour, which is often what a background wants.
Sepia as a tone, not a filter stack
The sepia option tints the luminance rather than layering brown over the picture.
Questions
How do I make an image pure black and white with no grey?
Choose "Pure black and white, no grey". The threshold is picked automatically from the picture, or set it yourself.
How do I convert an image to a black and white PDF?
Pick greyscale or pure black and white, set Save as to PDF, and download.
Why does my black and white photo look blotchy?
A photo has smooth shading that two tones cannot show. Turn on dithering, or use greyscale.
Is this the same as desaturating?
It is the correct version of it. Many tools average the channels, which is not how brightness works.
Does it help for laser engraving?
Yes. Engraving is driven by brightness, so converting with the right weights predicts the burn far better than an average does.