Grayscale Image Converter
Turn a photo black and white with the conversion you actually want, live on the picture, then download it at full resolution.
How it works
How to convert an image to grayscale?
Open the photo
Drag in a JPG, PNG or WebP, or pick one. It is read straight off your device — nothing is uploaded, so there is no size cap and no queue.
Pick a method
Nine of them, and they are genuinely different pictures. Luminance is the safe default; the red channel is the classic portrait conversion; the blue channel is the gritty, pushed-film one.
Set the amount and the tone
Amount decides how far towards grey — 100% is a true grayscale image, less leaves the colour showing through. Then brightness and contrast, which is what black and white lives or dies on.
Download it
Save as JPG, PNG or WebP. The conversion runs at the picture’s own resolution, so what you get is the full-size original in black and white — and nothing stamped in the corner.
What it does
Nine grayscale images, not one
Every grayscale converter has to answer one question per pixel: given a red, a green and a blue, how bright is this? There is no single correct answer, and the answers do not look alike — which is why most tools quietly pick one and this one hands you all nine. Photograph a red rose against green leaves: on the red channel the petals are almost white and the leaves almost black, and on the blue channel it is the other way round. Same photo, same amount of colour thrown away, completely different picture.
Nine conversion methods
Rec. 709 luminance, Rec. 601 luma, average, lightness, the lightest channel, the darkest channel, and red, green or blue on their own. A red rose over green leaves comes out near-white on one and near-black on another.
Weighted the way the eye sees
Luminance is not (R+G+B)/3. Green carries most of what we read as brightness and blue almost none, which is why the default is weighted 0.2126 / 0.7152 / 0.0722 and why it looks right.
Partial desaturation
The amount slider runs 0 to 100, so you can stop halfway and leave a hint of the original colour underneath — the faded look, rather than a hard switch.
Shades of gray
Cut the picture to as few as 2 levels, or anywhere up to 32. Two shades is a hard black-or-white threshold; the ones between are the posterised, screen-printed look.
Brightness and contrast
With the colour gone, contrast is the only thing left to separate one thing from another. Both sliders run after the conversion, so they act on the black and white picture you can see.
Hold to compare
Press and hold to see the colour original in the same frame at the same size. Let go and the grayscale is back.
Your own resolution
JPG, PNG or WebP with the quality in your hands, written at the picture’s own pixel size — never a preview blown back up.
Nothing leaves your device
The photo is read, converted and saved entirely in your browser. There is no upload, no account and no watermark.
Which method
Picking the right conversion
Luminance is the right default and the one to reach for when you have no reason to do anything else. The rest are worth knowing about for the shots where it is not.
| You want | Use | Why that one |
|---|---|---|
| A safe, natural black and white of anything | Luminance (Rec. 709) | Weighted the way the eye reads brightness, so tones land where you expect them to and nothing goes muddy |
| A portrait with smooth skin and a dark sky | Red channel | Skin is mostly red, so it goes pale and even; a blue sky has almost no red in it and drops to near-black |
| Something heavy, contrasty and dramatic | Darkest channel | Any colour at all reads as dark, so the picture keeps only what was genuinely bright |
| A high-key, washed, airy result | Lightest channel | Anything saturated goes bright, which lifts the whole picture away from black |
| A flat, graphic look for a logo or a screenshot | Average | Ignoring how the eye works flattens the separation between colours, which is exactly what flat artwork wants |
| Pure black and white with no greys at all | Any method, Shades of gray at 2 | Two levels is a threshold — every pixel is forced to one end or the other, which is what stencils and screen prints need |
Questions