What formula is used for the grayscale conversion?

Each pixel's luminance is calculated as 0.299 times the red channel plus 0.587 times the green channel plus 0.114 times the blue channel. This is the standard ITU-R BT.601 formula used in professional image editing software.

Does converting to grayscale reduce file size?

The output file is still a full-color image with RGB channels, so file size stays similar to the original. If you need a smaller grayscale file, compress the output with the Compress Image tool afterward.

What formats are supported?

PNG, JPG, and WEBP images up to 50 MB. The output format matches your input. PNG output is lossless. JPG and WEBP output use 92% quality.

Is my image sent to a server?

No. The conversion runs in your browser using the Canvas API and ImageData. Your image never leaves your device.

Can I convert a photo back to color after grayscale?

No. Converting to grayscale is a one-way operation. The original color information is discarded when the pixel values are replaced with luminance values. Keep your original file before converting.

Grayscale

Convert images to black and white in your browser.

Drop your files here
or click to browse
PNG, JPG, JPEG, WEBP · Max 25MB

Your files are processed locally and never leave your browser.

How it works

Choose a file

Drop a file or click to browse

Process

Adjust settings if needed, then process

Download

Get your result instantly

When to use this

Create print-ready art

Convert color images to grayscale for black-and-white print jobs.

Design mockups

Grayscale versions help test contrast and readability in UI design.

Reduce visual noise

Black-and-white photos work well for backgrounds and overlays.

Free online grayscale image converter

Convert PNG, JPG, and WEBP images to black and white in your browser. Drop your image and the conversion happens automatically. No upload required.

The tool uses the standard luminance formula to weight each color channel by how the human eye perceives brightness. Green contributes the most, followed by red, then blue. This produces more natural-looking grayscale results than a simple average.

Grayscale conversion is useful for document scanning workflows, artistic projects, reducing visual noise in technical images, or preparing assets for print.

All processing runs on your device. Nothing is uploaded, and no account is needed.

Frequently Asked Questions

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