Greyscale Color Converter
Enter a 3, 4, 6, or 8 digit HEX color and get a deterministic greyscale HEX value calculated locally.
A QUICK WALKTHROUGH
How to use this tool
- Enter a HEX color with or without #.
- The tool computes Rec. 709 luma (0.2126R + 0.7152G + 0.0722B) and rounds to the nearest 8-bit value.
- Copy the greyscale HEX result; a supplied alpha channel is preserved.
Explicit luma method
This converter uses gamma-encoded sRGB channel bytes with the Rec. 709 weights 0.2126, 0.7152, and 0.0722. The resulting byte is rounded with JavaScript Math.round.
HEX and alpha scope
Three and six digit HEX inputs produce six digit output. Four digit input is expanded to eight digits, and eight digit input stays eight digits; the alpha byte is preserved. No named colors, CSS functions, or wide-gamut spaces are parsed.
Local processing
The color is converted in this browser and is not uploaded or stored.
GOOD TO KNOW
Common questions
Which greyscale formula is used?
Rec. 709 weighted luma: 0.2126R + 0.7152G + 0.0722B, rounded to the nearest 8-bit channel value.
Is alpha changed?
No. A supplied alpha byte is copied unchanged; RGB-only input remains RGB-only.
Can I enter rgb() or a color name?
No. This focused tool accepts only 3, 4, 6, or 8 hexadecimal digits, optionally preceded by #.