Scan Cleanup · Browser Tool
Black & White Scan Converter
Convert any document image to pure black and white using a threshold algorithm. The threshold slider controls the cutoff point — lower values keep more light pixels as white, higher values keep more dark pixels as black. An adaptive threshold option handles uneven lighting and shadows automatically. Best for printed text documents, forms, and receipts where you want maximum contrast.
Input formats
Output formats
Common uses
- Create a high-contrast scan for printing or filing
- Prepare a document for OCR on systems that work better with B&W
- Reduce file size by converting to 1-bit B&W
- Create clean B&W photocopies of text documents
Limitations
- Pure B&W loses photographic detail — not suitable for photos with continuous tone.
- Very noisy scans may produce speckled B&W output — clean the scan first.
- Maximum image size: 30 MB.
Runs entirely in your browser
This tool processes your files locally using the Canvas API. Nothing is uploaded. Your files never leave your device.
Frequently asked questions
Use adaptive threshold when the lighting is uneven — for example, a document with shadows on one side. Adaptive threshold calculates the cutoff locally for each region of the image, handling brightness variation. Fixed threshold works best when the scan has uniform, even lighting.