Convert an image to grayscale locally - luminance-weighted black and white, format preserved. No upload.
Running locally on your device ...
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Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Turning a photo to grayscale removes all colour and keeps only the brightness of each pixel. This tool does it the correct, perceptual way: it weights red, green and blue by how the human eye sees them (the Rec. 601 luminance formula, roughly 30% red, 59% green, 11% blue) rather than a flat average, so skin tones, skies and foliage keep their natural relative lightness instead of looking muddy.
Grayscale is useful for black-and-white print, for a clean editorial look, for reducing file size, or to make an image recede behind coloured text. The output keeps your original format and dimensions - a PNG stays a PNG (with its transparency), a JPEG stays a JPEG - so it drops straight back into wherever the colour version came from.
Everything runs entirely locally in your browser on a canvas (no upload, even offline) - your image never leaves your device. The conversion is a per-pixel transform, so it is exact and repeatable. Animated images are flattened to a single frame; for a different look try the sepia or invert tools.
| Input formats | JPG, JPEG, PNG, WEBP |
|---|---|
| Output format | JPG |
| Batch processing | Yes |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: Converts an image to grayscale using the Rec. 601 luminance weighting (about 30% red, 59% green, 11% blue), per pixel. The original format and dimensions are preserved (PNG keeps transparency; JPEG flattens onto white). Animated inputs are reduced to a single frame. It is a fixed transform with no settings.
No. The conversion runs entirely locally in the browser on a canvas - even offline. Your image never leaves your device.
A flat average looks muddy because the eye is far more sensitive to green than to blue. Luminance weighting keeps the natural relative lightness of colours.
Yes. A PNG stays a PNG with its transparency; a JPEG stays a JPEG (flattened onto white). Dimensions are unchanged.
No. Grayscale discards the colour information, so keep your original if you need the colour version.