Apply a black and white image threshold

Useful for scanned forms, line art and experiments where subtle tones should become clean light or dark regions.

Turn an image into stark black and white using a chosen threshold, making shapes, lettering and contrast easier to isolate at a glance.

How to use

Open the photo or document you want to reduce to two tones, using a PNG, JPEG or WebP file.
Set the threshold value that decides when a pixel becomes white or black.
Watch fine lines and small shapes, because a high or low setting can erase details or fill them in.
Run the process, then download the black and white result.
Clear the working file before testing another setting on a different image.

Example

A designer prepares a stencil from a photo of leaves. They apply the black and white threshold, adjust the value to keep the main veins, and then use the result as a mask base in a graphic project.

Limits and formats

The output has only two tones and no smooth grey transitions.
Noisy images may turn into scattered speckles around edges.
Check thin lines before cutting or printing the result.
The threshold applies to the whole image, with no local adjustment.

Where processing happens

The conversion runs in your browser. Brightness values are analysed on your device, pixels are changed according to the selected threshold, and the final file is generated without being sent to an external service.

Frequently asked questions

What does the threshold value actually control?

It defines the brightness level where the image switches from dark to light. Pixels below that level become black, and pixels above it become white, so the setting changes how much of the picture falls into each group.

Can I use this for logos or line art?

Yes, clean line art and simple logos often work well because they already have strong contrast. If the source contains gradients or shadows, expect some shapes to change, and review the result at full size before using it.

Why does my scanned paper look dirty?

Paper texture, shadows and scanner noise can become black patches when the threshold is too low. Try a higher value so that the background stays white, while checking that faint letters or lines have not disappeared.