Black and white image
Turn a photo grayscale, pure black and white, or sepia.
Runs in your browser. Your files never leave your device.
- Grayscale, threshold or sepia
- Adjustable threshold level
- Batch convert
How to make an image black and white
- Drop your images here.
- Pick grayscale, threshold or sepia.
- Download the converted images.
Grayscale vs threshold vs sepia
| Grayscale | Threshold | Sepia | |
|---|---|---|---|
| Look | Full range of gray | Pure black or white only | Warm brown tint |
| Best for | Photos | Scanned text, line art | Vintage photo look |
| Adjustable | No | Threshold level | No |
Threshold is the setting many scanning apps use for black and white documents, since it turns faint pencil marks and a slightly gray background into a clean, printable image.
How grayscale is calculated
Grayscale is not a plain average of the three color channels. Each pixel is weighted 0.299 red, 0.587 green and 0.114 blue, matching how the human eye perceives brightness, so a bright green looks lighter in grayscale than an equally bright blue does.
Tips for threshold scans
- Raise the threshold level if the result loses light pencil marks or faint text.
- Lower it if scanned paper texture or shadows are showing up as black speckles.
- Threshold works best on high contrast originals like text and line drawings, not photos with smooth gradients.
Black and white image FAQ
What is the difference between grayscale and threshold?
Grayscale keeps every shade of gray for a smooth photo look. Threshold turns each pixel fully black or white, which suits scanned text and line art.
What does the threshold slider do?
Pixels brighter than the slider value turn white, and darker pixels turn black. Move it if a scan comes out too dark or too washed out.
What does sepia do?
It tints the photo with warm brown tones like an old print, instead of removing color completely.
Can I convert several photos at once?
Yes. Drop as many as you like and download them together as a ZIP.
Does grayscale use a simple average of red, green and blue?
No. It weights green the most and blue the least (0.299 red, 0.587 green, 0.114 blue for each pixel) instead of averaging the three equally, since the eye is more sensitive to green light. That is why a bright green object looks lighter in grayscale than an equally bright blue one.
Will this work on scanned documents?
Yes. Threshold mode is built for exactly this: pick a level that keeps the text dark and the paper background white.
Does converting to black and white reduce the file size?
Usually a little, since removing color detail gives the compressor less variation to store, though the drop is smaller than switching to a more compressed format.