Regular Expressions 101

Group 1((\d)(?!\2{3})){16}

{16}repeats the group contents below exactly 16 times:

Group 2(\d)

\da digit

Negative Lookahead(?!\2{3})

\2{3}the text saved by group 2, repeated exactly 3 times

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

Regular Expression

((\d)(?!\2{3})){16}

New

5123456789123456
6123456789123456
4123356789123456
5133336789123456
1234567890134443

5123456789123456
6123456789123456
4123356789123456
5133336789123456
1234567890134443