Threshold Image to Black and White Free
Runs 100% in your browser — your files never leave your device.
Convert a sketch into crisp line art, make a stencil, or build a high-contrast mask for design work. Pixels above the threshold become white, everything below becomes black, and you control the cutoff. The binarization happens in your browser.
How it works
- 1
Add your image
Drop a JPG, PNG, or WebP into the box or click to browse. Nothing is uploaded.
- 2
Threshold it
Tune the control until the effect looks right on your image.
- 3
Download the result
Click to apply and download the edited image in its original format.
About this tool
How thresholding works
Threshold collapses every pixel to pure black or pure white based on one brightness cutoff. Pixels brighter than the cutoff turn white; the rest turn black. The slider moves that cutoff, and the preview shows the balance shift in real time.
When to reach for it
Threshold turns sketches into line art, builds stencils for cutting, prepares images for engraving and laser cutters, and creates hard-edged masks. It is also a quick legibility test: if a design still reads in pure black and white, it reads anywhere.
Tips for the best result
Choose the cutoff based on what you want to keep, not on what looks natural. For signatures and sketches, stop at the point where thin strokes stay connected. Working from a photo? Try grayscale first to judge tones without color pulling your eye.
Frequently asked questions
Why did thin lines disappear at my threshold?
Light strokes sit close to the cutoff, and a small move pushes them to the white side. Lower the threshold until they reappear, or add contrast before thresholding to separate strokes from paper more decisively.
Will the original file change?
No — the threshold effect is applied to a working copy in memory. Your original file stays untouched on your device, and the download is a brand-new file.
Which formats and sizes work?
JPG, PNG, and WebP files up to 50 MB. The result downloads in the original format with dimensions unchanged.
Can I get grayscale back after thresholding?
No — thresholding discards everything between black and white, permanently. Keep the original file; the tool never modifies it, so you can re-run with a different cutoff anytime.