100% Client-Side • 0 B Data Leaves Browser
web
Hex Color Code Regex (#RGB and #RRGGBB)
Matches 3-digit or 6-digit CSS hexadecimal color notation.
Regular Expression Pattern:
/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/i
Valid Match Example:
#10b981
Invalid / Non-Match Example:
#12345
Regex Syntax Breakdown & Explanation
- •^# : Requires starting hash symbol
- •[A-Fa-f0-9]{6} : Matches full 6-digit hex format
- •| : Or
- •[A-Fa-f0-9]{3} : Matches shorthand 3-digit hex format
Implementation in Popular Languages
JavaScript / TypeScript
const regex = /^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/i;
const isValid = regex.test("#10b981");
console.log(isValid); // truePython (re)
import re
pattern = r"^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$"
match = re.match(pattern, "#10b981")
print(bool(match)) # TrueGo (regexp)
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$`)
fmt.Println(re.MatchString("#10b981"))
}Frequently Asked Questions
Frequently Asked Questions
Everything you need to know regarding specifications, syntax, and security best practices.
The regular expression pattern is /^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/i. Matches 3-digit or 6-digit CSS hexadecimal color notation.