Image Threshold
Convert any photo to pure black and white by brightness.
How to use
- 1 Drop an image onto the box, or click to choose a file.
- 2 Drag the threshold slider to set the black/white cutoff.
- 3 Toggle invert if you want the tones swapped.
- 4 Click Download PNG to save the two-tone image.
About Image Threshold
The Image Threshold tool reduces a photo to two tones — pure black and pure white — by comparing each pixel’s brightness against a cutoff you control.
Pixels brighter than the threshold turn white; everything darker turns black.
The result is a high-contrast, stencil-like image that is perfect for line art, logos, screen-printing separations, laser-cutting masks, dithered aesthetics or simply making faint text legible.
Brightness is measured with the perceptual Rec. 601 luma formula, which weights green more heavily than red and blue, matching how the human eye judges lightness.
That makes the split land where you expect rather than producing a muddy or uneven cut.
Drag the threshold slider and the preview updates instantly, so you can find the exact point where detail appears or disappears.
An invert toggle swaps which side becomes white, handy for dark backgrounds or producing a negative.
The conversion is a tiny pure function over the raw pixel array, and the whole process runs locally with the Canvas API — your image is never uploaded or stored.
Once the contrast looks right, download a lossless PNG that preserves the crisp two-tone edges.
FAQ
How is the cutoff decided?
Each pixel’s brightness is computed with the Rec. 601 luma formula; pixels at or above your chosen level become white, the rest become black.
Is my image uploaded anywhere?
No. The threshold is applied with the Canvas API inside your browser, so the picture never leaves your device.
What is the invert option for?
It swaps black and white, which is useful for light-on-dark artwork or when you want a negative of the result.