Black and White Image Converter
Choose a picture and a style to turn it into black and white.
Your picture is converted inside this page and never uploaded.
What this tool does
Choose a picture, then pick a style. Grayscale keeps the shades of grey, using the standard luminance weights. Pure black and white turns each pixel black or white around a threshold you set, and dithering uses black and white dots to imitate shades. Download it as a PNG or JPEG.
Converts colours to brightness values and then to grey, black and white, or dithered dots.
Provides an invert option and a choice of output format.
How to use it
- Choose an image.
- Pick grayscale, pure black and white or dithered.
- For black and white, set the threshold.
- Invert if needed and press Download.
Why use this tool
Offers three real ways to remove colour in one tool: smooth grayscale, hard black and white by a threshold you set, and Floyd-Steinberg dithering that fakes grey with black and white dots. Black and white pictures are needed for printing, for stencils and signs, for e-paper and for artistic photos. The three styles give very different results, so being able to compare them on your own picture saves guesswork.
Why we built it
We built the black and white converter to offer grayscale, threshold and dithered styles side by side on your own picture. Adjust tone with the image filter editor and turn photos into drawings with the photo to sketch tool.
Who this tool is for
- Photographers wanting a monochrome look
- Makers preparing stencils and signs
- Anyone printing in black and white
When to use it
- Making a photo suitable for a black and white printer or a laser cutter.
- Preparing a stencil, logo or sign.
- Giving a photo a classic monochrome look.
- Reducing colour ink on a print.
How it works
Each pixel's brightness is 0.2126 R + 0.7152 G + 0.0722 B, the Rec. 709 luminance weights, which match how bright the eye finds each colour. Grayscale sets red, green and blue to that value. The threshold style makes the pixel white if it is brighter than the threshold and black if not. Floyd-Steinberg dithering also rounds each pixel to black or white, but passes the rounding error on to the neighbouring pixels, so areas of mid-grey become an even pattern of dots.
Example: pure red (255, 0, 0) has a brightness of 54 and pure green (0, 255, 0) has 182, which is why green looks lighter than red in grayscale.
Transparency is kept in the preview but JPEG has none, so a JPEG download has a solid background.
What you give it, and what you get back
| Item | Details |
|---|---|
| Image | A JPG, PNG, WebP or other picture your browser can open. |
| Style, threshold, invert | Grayscale, black and white or dithered; a threshold from 1 to 254; and an invert switch. |
| Output | A PNG or JPEG at the image's size (up to 4,000 pixels on the long edge). |
Issues you may run into
| What you see | Why it happens | What to do |
|---|---|---|
| The picture is all black or all white | The threshold is too high or too low. | Move the threshold slider. |
| Dithering looks noisy | It is a dot pattern by design. | Use grayscale or a threshold for a cleaner look. |
| Edges look jagged in black and white | Only two tones are available. | Use a higher resolution picture or grayscale. |
Assumptions and limitations
- No contrast or brightness sliders.
- The long edge is limited to 4,000 pixels.
Frequently asked questions
How do I convert a photo to black and white?
Choose the picture and keep the Grayscale style, then download it.
What is the difference between grayscale and black and white?
Grayscale keeps shades of grey. Pure black and white has only two tones.
What is dithering?
A way of showing shades using only black and white dots, by spreading each pixel's rounding error to its neighbours.
What does the threshold do?
Pixels brighter than it become white, and the rest become black.
Is my picture uploaded?
No. It is converted in your browser.
Is anything sent to a server?
No. Everything runs in your browser and nothing leaves the page.