Threshold Tool
Convert photos into clean black and white binary images using adjustable thresholds.
Upload an image
Drag & drop or browse
Binarization Settings
Binary Inversion swaps white and black values. Essential for creating stencils from dark subjects.
Use a lower threshold to capture shadow details, and a higher threshold for clean silhouettes.
Threshold Tool
The Threshold tool is essential for technical image prep and artistic binarization. It converts any image into a high-contrast 'binary' output (pure black and pure white). By adjusting the threshold value, you control exactly which brightness levels become black and which become white. This is perfect for cleaning up scanned documents, preparing stencils for CNC/Laser cutters, or creating bold graphic art. The cutoff is applied to Rec. 709 luminance, 21.26% red, 71.52% green, and 7.22% blue, so brightness is judged the way human vision weights it rather than by naive averaging. Every pixel above the cutoff becomes pure white and everything at or below becomes pure black, with alpha forced opaque. The preview re-renders as you drag the slider, the Invert switch flips the logic for light subjects on dark grounds, and the full-resolution PNG is generated on a local canvas.
Why This Tool Exists
What makes this useful — and why I built it this way.
High-Contrast Binarization: Convert color images into striking black-and-white formats.
Adjustable Threshold: Fine-tune the division level between dark and light pixels.
Clean Edge Isolation: Perfect for vectorizing or stencil preparation.
Instant Feedback: The binary preview updates while you drag, so tuning takes seconds.
When You'd Use This
Real situations where this tool saves the day.
Line Art Scanning: Clean up handwritten notes, sketches, and documents to pure black-and-white.
Stencil Creation: Prepare images for screen printing, stencils, or engraving.
Computer Vision Prep: Segment images to prepare objects for shape-detection algorithms.
Barcode Cleanup: Flatten noisy scans to crisp black-and-white before decoding them.
Using Threshold Tool
It's straightforward — here's how it works.
Upload the image or document you want to binarize.
Move the threshold slider to find the perfect cutoff point.
Check the 'Invert' box if you need light areas to be black.
Watch the live preview update as you tune the cutoff.
Download the results as a high-fidelity PNG.
Questions People Ask
Honest answers about how this works.
Is this good for cleaning up pencil sketches?
Short answer: Yes! It's the best way to turn a rough pencil sketch into a clean black-and-white ink-style line drawing. Scan or photograph the sketch, set the cutoff near the middle of the slider, and drag until the paper turns pure white while the strokes stay solid black.
What format is the output?
We export a full-resolution PNG where every pixel is either pure black or pure white, with no compression artifacts or gray fringes along the edges. Because it is lossless, the same file can go straight into a vector tracer, a screen-printing workflow, or a laser cutter.
What happens to a color or grayscale image?
Color pixels are first converted to Rec. 709 luminance, then every pixel is compared against your cutoff: above it becomes white, at or below becomes black, and the result is a two-tone PNG with no gray values left.
Discover More Tools
Hand-picked utilities to speed up your workflow.