Validate hex color

Check CSS hexadecimal colors in three-, four-, six-, or eight-digit notation.

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ToolHex Color Validator
Input
Output
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Preview

How it works

The value begins with # and contains exactly 3, 4, 6, or 8 hexadecimal digits. Three and four digits are shorthand channels; four and eight include alpha, while six is the ordinary sRGB form.

  • The accepted lengths are CSS hexadecimal forms.
  • The required # separates colors from bare numbers.

Worked example

Valid 6-Digit Hex
Validate a standard 6-digit hex color code
Input
											#FF5733
Output
												Valid hex color (6-digit): #FF5733

When to use this

CSS themes, design systems, and SVG or Canvas paint inputs validate colors.

Edge cases

  • #abc expands repeated channel nibbles.
  • #abcd includes alpha and is not opaque #abcd00.
  • #GGHHII fails because only hex digits are permitted.

References