Regular Expressions 101

Save & Share

  • Save Regex
    ctrl+s
  • Update Regex
    ctrl+⇧+s

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8

Function

  • Match
  • Substitution
  • List
  • Unit Tests
/
^((https?|ftp):\/\/([a-z0-9_\x{00a1}-\x{ffff}]+([a-z0-9\-:@\x{00a1}-\x{ffff}]*[a-z0-9\x{00a1}-\x{ffff}]+)?([\.\-_][a-z0-9\x{00a1}-\x{ffff}]+)+)(\/[0-9a-z\-_.$%()\x{00a1}-\x{ffff}]*)*(:\d*)?\/?([?|#]([\w\d=_\-$&%.])*)*)$
/
gm
^ asserts position at start of a line
1st Capturing Group
((https?|ftp):\/\/([a-z0-9_\x{00a1}-\x{ffff}]+([a-z0-9\-:@\x{00a1}-\x{ffff}]*[a-z0-9\x{00a1}-\x{ffff}]+)?([\.\-_][a-z0-9\x{00a1}-\x{ffff}]+)+)(\/[0-9a-z\-_.$%()\x{00a1}-\x{ffff}]*)*(:\d*)?\/?([?|#]([\w\d=_\-$&%.])*)*)
2nd Capturing Group
(https?|ftp)
1st Alternative
https?
http
matches the characters http literally (case sensitive)
s
matches the character s with index 11510 (7316 or 1638) literally (case sensitive)
2nd Alternative
ftp
ftp
matches the characters ftp literally (case sensitive)
: matches the character : with index 5810 (3A16 or 728) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
3rd Capturing Group
([a-z0-9_\x{00a1}-\x{ffff}]+([a-z0-9\-:@\x{00a1}-\x{ffff}]*[a-z0-9\x{00a1}-\x{ffff}]+)?([\.\-_][a-z0-9\x{00a1}-\x{ffff}]+)+)
Match a single character present in the list below
[a-z0-9_\x{00a1}-\x{ffff}]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
_ matches the character _ with index 9510 (5F16 or 1378) literally (case sensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case sensitive)
4th Capturing Group
([a-z0-9\-:@\x{00a1}-\x{ffff}]*[a-z0-9\x{00a1}-\x{ffff}]+)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[a-z0-9\-:@\x{00a1}-\x{ffff}]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
:@
matches a single character in the list :@ (case sensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case sensitive)
Match a single character present in the list below
[a-z0-9\x{00a1}-\x{ffff}]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case sensitive)
5th Capturing Group
([\.\-_][a-z0-9\x{00a1}-\x{ffff}]+)+
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
Match a single character present in the list below
[\.\-_]
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
_ matches the character _ with index 9510 (5F16 or 1378) literally (case sensitive)
Match a single character present in the list below
[a-z0-9\x{00a1}-\x{ffff}]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case sensitive)
6th Capturing Group
(\/[0-9a-z\-_.$%()\x{00a1}-\x{ffff}]*)*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
Match a single character present in the list below
[0-9a-z\-_.$%()\x{00a1}-\x{ffff}]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
_.$%()
matches a single character in the list _.$%() (case sensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case sensitive)
7th Capturing Group
(:\d*)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
: matches the character : with index 5810 (3A16 or 728) literally (case sensitive)
\d
matches a digit (equivalent to [0-9])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\/
matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
8th Capturing Group
([?|#]([\w\d=_\-$&%.])*)*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
Match a single character present in the list below
[?|#]
?|#
matches a single character in the list ?|# (case sensitive)
9th Capturing Group
([\w\d=_\-$&%.])*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
Match a single character present in the list below
[\w\d=_\-$&%.]
\w matches any word character (equivalent to [a-zA-Z0-9_])
\d matches a digit (equivalent to [0-9])
=_
matches a single character in the list =_ (case sensitive)
\- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
$&%.
matches a single character in the list $&%. (case sensitive)
$ asserts position at the end of a line
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Generated Code

Loading code sample...
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report.
For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php