Convert images to monochrome - B&W, sepia, and more.
Turn any photo into a single-tone monochrome image. Pure black and white, warm sepia, cool cyanotype, or custom tints. Real-time preview, no upload, no signup.
Drop an image here, or click to browse
JPG, PNG, or WebP - preview updates in real time
How to make an image monochrome online.
Upload your photo
Drag any JPG, PNG, or WebP file onto the upload area. No file size limit - large photos process just as fast.
Pick a monochrome style
Click Pure B&W for classic grayscale. Choose Sepia for warm vintage tones, Cyanotype for cool blue, or any other tint. Preview updates instantly.
Download
Click Download Monochrome. The full-resolution result saves in your original format. Adjust JPG quality before downloading if needed.
Frequently asked questions.
How does the monochrome conversion work?
The converter calculates the luminance of each pixel using the standard ITU-R BT.601 formula: 0.299R + 0.587G + 0.114B. This weights green highest because human eyes are most sensitive to green light. The result is a single brightness value per pixel. For pure black and white, that value is used for all three channels. For tinted styles like sepia, the brightness is multiplied by the tint color to produce a monochrome image with a warm or cool cast.
What monochrome styles are available?
Six styles: Pure B&W (neutral gray values only), Sepia (warm brown tones that mimic aged silver prints), Cyanotype (blue tones from the historical cyanotype printing process), Lavender (cool purple tint), Warm Tone (subtle warm cast without the strong brown of sepia), and Cool Green (muted green cast popular in editorial photography). Click any style and the preview updates instantly.
What is the difference between monochrome and grayscale?
Grayscale is technically a subset of monochrome. Grayscale means specifically neutral gray values (no color at all). Monochrome means "one color" - that color can be gray, brown (sepia), blue (cyanotype), or any other single hue. This tool offers both: Pure B&W is true grayscale, while the tinted options are monochrome. In everyday use, people use the terms interchangeably.
Does converting to monochrome reduce file size?
Yes, typically by 10-30% for JPG output. Monochrome images have less color variation, which means the JPG encoder achieves better compression ratios. A 2 MB color photo might compress to 1.4-1.6 MB as monochrome at the same quality setting. PNG files see similar but smaller improvements. The reduction depends on how colorful the original was - a mostly gray photo barely shrinks, while a vibrant sunset photo shows a larger difference.
Can I convert a photo to monochrome on my phone?
Yes. Open this page in Safari (iPhone) or Chrome (Android). Upload a photo, tap a monochrome style, and download. The real-time preview works on mobile with full touch support. All processing happens on your device, so it works on any connection speed and no data is sent to any server.
Are my images uploaded to a server?
No. The monochrome conversion runs entirely in your browser using the Canvas API and direct pixel manipulation in JavaScript. Your image never leaves your device. Verify by opening browser developer tools (F12), switching to the Network tab, and using the tool - zero outgoing file requests.
What image formats are supported?
JPG, JPEG, PNG, and WebP input. Output format matches the input - JPG in gives JPG out, PNG in gives PNG out. JPG quality is adjustable for JPG output. There is no file size limit beyond browser memory. Images up to 8000x6000 pixels process smoothly on modern devices.