Grayscale
Convert to black and white.
This runs in your browser. Nothing is uploaded.
About Grayscale
Converts an image to black and white in one click using the standard perceptual brightness weighting, with no settings to choose and the maths running in your browser.
Black and white is a requirement more often than it's a style choice: forms asking for monochrome scans, documents headed for a laser printer, diagrams that have to survive being printed without colour, photographs that read better without a distracting palette. There's nothing to configure on this page — drop the image in, apply, download.
Each pixel's three channels collapse into one brightness value using the weighting human vision actually uses: roughly 21 percent red, 72 percent green, 7 percent blue. Green dominates because your eye is most sensitive to it. That single value is then written back into all three channels, which is why the output is still technically an RGB image. Transparency passes through untouched.
A fixed weighting means colours that differ in hue but match in brightness converge on the same grey. A red logo on a green background, a chart whose category colours are all mid-tone, blue sky behind autumn leaves — any of these can go mushy. If separation matters, pull the colours apart with saturation, hue or levels first, then convert. The conversion itself is one-way, so keep your original.
How to use Grayscale
- 1Drop your image onto the panel or click to browse.
- 2Click Apply preview — there are no settings to change.
- 3Click Download to save the black-and-white version as a PNG.
What it won't do
- No channel mixer and no colour-filter emulation — one fixed weighting only.
- Colours of equal brightness become the same grey, which can flatten a chart or a logo.
- Saves as an RGB PNG rather than a true single-channel grayscale file.
Common questions
What's the difference between grayscale and desaturating an image?
Here, nothing you would see. Dragging saturation to -100 uses the same brightness weighting and lands on the same grey values. The difference lives elsewhere: some software desaturates by averaging the three channels equally, which gives duller and less accurate results. This page uses the perceptual weighting, in one click, with no sliders to get wrong.
Will the black-and-white file be smaller?
A little, but less than you'd expect. The download is a PNG that still carries three colour channels, each holding the same value, rather than switching to a true single-channel grayscale format. PNG compression does exploit that repetition, so files shrink somewhat. If size is the actual goal, run the result through a compressor.
Can I get the colour back afterwards?
No. Three numbers per pixel are reduced to one, and which colours produced that brightness isn't recorded anywhere. Keep the original file. If you wanted a coloured monochrome look rather than neutral grey, the duotone tool maps brightness onto two colours you choose, and starting from your colour original gives a better result.
Will converting to greyscale flatten a transparent logo?
No. The alpha channel passes straight through, so a transparent PNG logo comes back with the same transparent background and grey artwork. Semi-transparent pixels keep their exact opacity as well, which matters for anti-aliased edges — they stay smooth instead of picking up a white halo.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation