Threshold Image
Convert any photo to pure black and white — every pixel becomes one or the other based on a brightness cutoff you set with a live slider. Free, private, and instant — processed in your browser, never uploaded.
Upload an image
Drop image here
or click to browse
Options
Live cutoff slider
Drag the threshold from 0 to 255 to control how much of the image turns white versus black in real time.
100% private
Your image is processed entirely in your browser using the Canvas API — nothing is ever uploaded to a server.
Free and unlimited
No signup, no watermark, no daily limit. Process as many images as you like.
How to threshold an image
Upload your image
Drag and drop or click to select a JPG, PNG, or WebP image.
Set the cutoff
Drag the threshold slider until the black-and-white split looks right in the live preview.
Pick a format
Choose PNG to keep transparency or JPG for the smallest file size.
Download
Click download to save the thresholded image to your device.
Frequently asked questions
How do I convert an image to pure black and white?
Upload your image above and drag the threshold slider to set the brightness cutoff. The preview updates live, then click download to save it. Everything runs in your browser.
Is the threshold tool free?
Yes — completely free and unlimited. No signup, no account, no watermark, no daily limit.
Are my files uploaded to a server?
No. The thresholding happens entirely in your browser on your device. Your image never leaves your computer, so it stays fully private.
What does the threshold slider do?
It sets the brightness level that decides each pixel. Pixels brighter than the threshold turn white and the rest turn black, so a lower value keeps more white and a higher value keeps more black.
Threshold another image
Drop in a new photo to convert it to black and white — free and unlimited, no signup required.
Choose The Right Tool
Why this page exists
Use threshold to convert any photo to pure black and white — every pixel becomes one or the other based on a brightness cutoff you set with a live slider.
Best for
- High-contrast, two-tone, and stencil-style art
- Cleaning up scanned text and line drawings
- Bold silhouette and screen-print graphics