Threshold Image
Reduce a photo to pure black and white with an adjustable brightness cutoff, entirely in your browser.
Input
Processed entirely in your browser — the image is never uploaded to a server.
Pixels brighter than this value become white, darker pixels become black.
Output
Your edited image will appear here.
Guides
Turn a photo into pure black and white with a single adjustable cutoff — the Threshold Image tool compares every pixel's brightness against a level you choose and snaps it to either solid white or solid black, with nothing in between. It's the classic look behind high-contrast line art, stencil-ready graphics, and scanned-document cleanup.
How it works
Upload an image, then adjust one slider:
- Threshold Level — the brightness cutoff, from 0 to 255. Pixels at or brighter than this value become white; darker pixels become black. A low threshold keeps almost everything white (only the darkest pixels turn black); a high threshold keeps almost everything black (only the brightest pixels turn white). The default, 128, sits at the midpoint.
Brightness here is measured as luminance — the same perceptually-weighted mix of red, green and blue that display and print devices use to judge how light or dark a color looks, rather than a flat average of the three channels. That's why a saturated pure blue and a saturated pure red, even at "the same" numeric intensity, can end up on different sides of the cutoff: blue reads as darker to the eye, and the tool treats it that way.
The result renders instantly as you move the slider. You can download the result as an SVG file, or copy its source markup directly.
Tips
- Threshold works best on images with clear contrast between subject and background — a scanned document, a logo, or a photo with strong lighting will separate cleanly, while flat, evenly-lit photos can turn into a single solid block of color.
- If the result is mostly one color, nudge the slider toward the middle of the range where most of your image's brightness values actually sit — try the far ends first to see which way the balance tips, then work inward.
- Combine this with a brightness or contrast adjustment beforehand (in an image editor) if you need to push more detail above or below the cutoff before thresholding.
- The downloaded SVG stays crisp at any size since it's a vector wrapper around your original image — resizing it doesn't lose quality the way a rasterized export would.