Regular Expressions 101

Pro

\Bnot an ASCII word boundary

#the literal # (35₁₀ / 43₈ / 23₁₆)

Group 1([a-fA-F0-9]{6}|[a-fA-F0-9]{3})

1st Alternative[a-fA-F0-9]{6}

Character Class[a-fA-F0-9]{6}

{6}matches exactly 6 characters from the set below:

a-fone character from a (97₁₀) to f (102₁₀) (case sensitive)

A-Fone character from A (65₁₀) to F (70₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

2nd Alternative[a-fA-F0-9]{3}

Character Class[a-fA-F0-9]{3}

{3}matches exactly 3 characters from the set below:

a-fone character from a (97₁₀) to f (102₁₀) (case sensitive)

A-Fone character from A (65₁₀) to F (70₁₀) (case sensitive)

0-9one character from 0 (48₁₀) to 9 (57₁₀)

\ban ASCII word boundary

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

\B#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})\b

#fff
#fefefe
#242424
#24ff33
#24ff3o // o is not a valid hex value
#ffg // g is not a valid hex value

#fff
#fefefe
#242424
#24ff33
#24ff3o // o is not a valid hex value
#ffg // g is not a valid hex value