What you need
Choose one authorised JPEG, PNG, or WebP image up to 20 MB and 12 million decoded pixels. Animated frames are not processed.
Image Tools / Local studio
Convert a colour image to neutral luminance tones with visible limits and browser-local processing while preserving transparent pixels.
Step 1 / Source
Or browse for a JPEG, PNG, or WebP image that you own or are authorised to edit.
One file · up to 20 MB · maximum 50 megapixelsStep 2 / Output
This effect uses a fixed transformation, so no strength estimate is required. Pixel processing stays in this browser tab.
The selected image is decoded and re-encoded inside this browser tab.
After download, the preview URL, decoded bitmap, canvas, and selected source reference are cleared.
Nirmion cannot remove the finished file from your device or browser download history.
Workflow guide
Choose one authorised JPEG, PNG, or WebP image up to 20 MB and 12 million decoded pixels. Animated frames are not processed.
Compare a campaign photo in grayscale to verify tonal separation before committing to a monochrome layout.
Download a separate grayscale image. Dimensions remain unchanged unless the selected encoder handles the source differently.
Decision guide
The tool calculates weighted luminance from red, green, and blue, then writes that neutral value to all three channels.
Grayscale does not guarantee print neutrality, accessibility contrast, or correct colour-profile conversion. Browser-local processing avoids a Nirmion file upload, but it does not remove copies already stored elsewhere.
W3C Filter Effects Module Level 1Good to know
Questions answered
No. For supported JPEG, PNG, and WebP inputs, decoding, image grayscale maker, canvas rendering, and export run in your current browser tab. Nirmion does not send the selected image to its API for this workflow. The downloaded file is a new derivative; your original device file remains unchanged and should be retained when future editing or verification matters.
The tool calculates weighted luminance from red, green, and blue, then writes that neutral value to all three channels. The operation is applied to decoded RGB pixels while the alpha channel is preserved. It does not resize the canvas, recover clipped source detail, identify subjects, or infer a professionally correct look. Inspect representative shadows, midtones, highlights, edges, text, and transparent areas before relying on the exported copy.
Grayscale does not guarantee print neutrality, accessibility contrast, or correct colour-profile conversion. The workspace accepts one supported still image up to 20 MB and limits pixel-intensive effects to 12 million decoded pixels for predictable browser memory use. Output also depends on the browser encoder and selected format. Animated images, raw camera development, colour-profile calibration, and batch processing are outside this tool's scope.