Regular Expressions 101

^start of line

Negative Lookahead(?!666|000|9[0-9]{2})

1st Alternative666

666the literal text 666

2nd Alternative000

000the literal text 000

3rd Alternative9[0-9]{2}

9the literal 9 (57₁₀ / 71₈ / 39₁₆)

Character Class[0-9]{2}

{2}matches exactly 2 characters from the set below:

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

Character Class[0-9]{3}

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

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

Character Class[-]?

?matches at most one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookahead(?!00)

00the literal text 00

Character Class[0-9]{2}

{2}matches exactly 2 characters from the set below:

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

Character Class[-]?

?matches at most one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookahead(?!0{4})

0{4}the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated exactly 4 times

Character Class[0-9]{4}

{4}matches exactly 4 characters from the set below:

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

$end of line

Global pattern flags

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?!666|000|9[0-9]{2})[0-9]{3}[-]?(?!00)[0-9]{2}[-]?(?!0{4})[0-9]{4}$

New

123-45-6789
123456789
001341343
888-03-1785
888-04-0001


666-23-1234
666231234
000-65-1343
000651343
905-31-6375
905316375
888-00-1785
888001785
888-04-0000
888040000
666-00-0000
666-01-4050

Regular Expression

Substitution