Tiny Toolkit

Grayscale Image Tool

Convert any photo or graphic to grayscale instantly, using a luminance-weighted algorithm that matches how human eyes perceive brightness. The result looks more natural than a simple average of RGB channels, preserving perceived contrast across the image. Download the output as a PNG — all processing happens in your browser via the Canvas API.

All processing happens in your browser. No data is sent to any server.

Frequently Asked Questions

How does the grayscale conversion work?
The tool uses the browser's Canvas API with a CSS filter set to grayscale(100%). This applies the standard luminance-based conversion, weighting red, green, and blue channels according to human color perception (roughly 21% red, 72% green, 7% blue), which produces a natural-looking result.
What file format is the download?
The tool always downloads a PNG. PNG is lossless, so the grayscale values are preserved exactly. If you need a smaller file, you can convert the downloaded PNG to JPEG using an image converter.
Is my image uploaded to a server?
No. Processing happens entirely in your browser using the Canvas API. Your image never leaves your device.

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