Image Grayscale
Apply a grayscale or sepia effect and save the result as PNG. The preview is intended for visual treatment, not for contrast certification or a colour-managed print proof.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
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How to use this tool
Choose an image and an effect. Grayscale combines RGB using weights 0.299, 0.587 and 0.114; sepia uses a different channel matrix to produce its warm-toned appearance.
Results and examples
In the grayscale output, each pixel has equal red, green and blue channels. A pure red pixel therefore becomes a relatively dark gray, while its alpha transparency is retained.
Limitations
- These grayscale weights are not the linear relative-luminance calculation used by WCAG.
- PNG output does not retain every original metadata field or animation frame.
Fields
| Field | Guidance and constraints |
|---|---|
| Image | Check the unit and format displayed beside this field. |
| Effect | Check the unit and format displayed beside this field. |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
How is grayscale produced?
In the grayscale output, each pixel has equal red, green and blue channels. A pure red pixel therefore becomes a relatively dark gray, while its alpha transparency is retained.
Can it certify accessible contrast?
These grayscale weights are not the linear relative-luminance calculation used by WCAG. PNG output does not retain every original metadata field or animation frame.
