Please enable JavaScript to use regex101
/
^
r
e
g
e
x
[
\
-
_
]
?
1
0
1
$
/
i
Reg
ular
Ex
pressions
101
Upgrade to Pro
Enterprise
Community Library
How to contribute
x
IPv4 validation using recursion
Open Workspace
PCRE (Legacy)
Match
Created 2015-06-09 14:46
1
Regular Expression
/
^
(
2
[
0
-
4
]
\d
|
25
[
0
-
5
]
|
1
\d\d
|
\d\d
?
)
\.
(?1)
\.
(?1)
\.
(?1)
$
/
gm
Description
Validate IPv4 addresses using PCRE's recursion patterns.
Submitted by
Captain Haddock