Regular Expressions 101

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/
\b(?:(?:https?|ftp):\/\/)(?:\S+(?::\S*)?@)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)*(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?\b
/
gi
\b assert position at a word boundary: (^\w|\w$|\W\w|\w\W)
Non-capturing group
(?:(?:https?|ftp):\/\/)
Non-capturing group
(?:https?|ftp)
1st Alternative
https?
http
matches the characters http literally (case insensitive)
s
matches the character s with index 11510 (7316 or 1638) literally (case insensitive)
2nd Alternative
ftp
ftp
matches the characters ftp literally (case insensitive)
: matches the character : with index 5810 (3A16 or 728) literally (case insensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
Non-capturing group
(?:\S+(?::\S*)?@)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\S
matches any non-whitespace character (equivalent to [^\r\n\t\f\v ])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
Non-capturing group
(?::\S*)?
? 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 insensitive)
\S
matches any non-whitespace character (equivalent to [^\r\n\t\f\v ])
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
@ matches the character @ with index 6410 (4016 or 1008) literally (case insensitive)
Non-capturing group
(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)*(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,})))
1st Alternative
(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))
Negative Lookahead
(?!10(?:\.\d{1,3}){3})
Assert that the Regex below does not match
10
matches the characters 10 literally (case insensitive)
Non-capturing group
(?:\.\d{1,3}){3}
{3} matches the previous token exactly 3 times
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
\d
matches a digit (equivalent to [0-9])
{1,3} matches the previous token between 1 and 3 times, as many times as possible, giving back as needed (greedy)
Negative Lookahead
(?!127(?:\.\d{1,3}){3})
Assert that the Regex below does not match
127
matches the characters 127 literally (case insensitive)
Non-capturing group
(?:\.\d{1,3}){3}
{3} matches the previous token exactly 3 times
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
\d
matches a digit (equivalent to [0-9])
{1,3} matches the previous token between 1 and 3 times, as many times as possible, giving back as needed (greedy)
Negative Lookahead
(?!169\.254(?:\.\d{1,3}){2})
Assert that the Regex below does not match
169
matches the characters 169 literally (case insensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
254
matches the characters 254 literally (case insensitive)
Non-capturing group
(?:\.\d{1,3}){2}
{2} matches the previous token exactly 2 times
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
\d
matches a digit (equivalent to [0-9])
{1,3} matches the previous token between 1 and 3 times, as many times as possible, giving back as needed (greedy)
Negative Lookahead
(?!192\.168(?:\.\d{1,3}){2})
Assert that the Regex below does not match
192
matches the characters 192 literally (case insensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
168
matches the characters 168 literally (case insensitive)
Non-capturing group
(?:\.\d{1,3}){2}
{2} matches the previous token exactly 2 times
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
\d
matches a digit (equivalent to [0-9])
{1,3} matches the previous token between 1 and 3 times, as many times as possible, giving back as needed (greedy)
Negative Lookahead
(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})
Assert that the Regex below does not match
172
matches the characters 172 literally (case insensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
Non-capturing group
(?:1[6-9]|2\d|3[0-1])
1st Alternative
1[6-9]
1 matches the character 1 with index 4910 (3116 or 618) literally (case insensitive)
Match a single character present in the list below
[6-9]
6-9 matches a single character in the range between 6 (index 54) and 9 (index 57) (case insensitive)
2nd Alternative
2\d
2 matches the character 2 with index 5010 (3216 or 628) literally (case insensitive)
\d matches a digit (equivalent to [0-9])
3rd Alternative
3[0-1]
3 matches the character 3 with index 5110 (3316 or 638) literally (case insensitive)
Match a single character present in the list below
[0-1]
0-1 matches a single character in the range between 0 (index 48) and 1 (index 49) (case insensitive)
Non-capturing group
(?:\.\d{1,3}){2}
{2} matches the previous token exactly 2 times
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
\d
matches a digit (equivalent to [0-9])
{1,3} matches the previous token between 1 and 3 times, as many times as possible, giving back as needed (greedy)
Non-capturing group
(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])
1st Alternative
[1-9]\d?
Match a single character present in the list below
[1-9]
1-9 matches a single character in the range between 1 (index 49) and 9 (index 57) (case insensitive)
\d
matches a digit (equivalent to [0-9])
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
2nd Alternative
1\d\d
1 matches the character 1 with index 4910 (3116 or 618) literally (case insensitive)
\d matches a digit (equivalent to [0-9])
\d matches a digit (equivalent to [0-9])
3rd Alternative
2[01]\d
2 matches the character 2 with index 5010 (3216 or 628) literally (case insensitive)
Match a single character present in the list below
[01]
01
matches a single character in the list 01 (case insensitive)
\d matches a digit (equivalent to [0-9])
4th Alternative
22[0-3]
22
matches the characters 22 literally (case insensitive)
Match a single character present in the list below
[0-3]
Non-capturing group
(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}
{2} matches the previous token exactly 2 times
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
Non-capturing group
(?:1?\d{1,2}|2[0-4]\d|25[0-5])
1st Alternative
1?\d{1,2}
1
matches the character 1 with index 4910 (3116 or 618) literally (case insensitive)
\d
matches a digit (equivalent to [0-9])
{1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
2nd Alternative
2[0-4]\d
2 matches the character 2 with index 5010 (3216 or 628) literally (case insensitive)
Match a single character present in the list below
[0-4]
0-4 matches a single character in the range between 0 (index 48) and 4 (index 52) (case insensitive)
\d matches a digit (equivalent to [0-9])
3rd Alternative
25[0-5]
25
matches the characters 25 literally (case insensitive)
Match a single character present in the list below
[0-5]
Non-capturing group
(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
Non-capturing group
(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4])
1st Alternative
[1-9]\d?
Match a single character present in the list below
[1-9]
1-9 matches a single character in the range between 1 (index 49) and 9 (index 57) (case insensitive)
\d
matches a digit (equivalent to [0-9])
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
2nd Alternative
1\d\d
1 matches the character 1 with index 4910 (3116 or 618) literally (case insensitive)
\d matches a digit (equivalent to [0-9])
\d matches a digit (equivalent to [0-9])
3rd Alternative
2[0-4]\d
4th Alternative
25[0-4]
2nd Alternative
(?:(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)*(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,}))
Non-capturing group
(?:(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)
Non-capturing group
(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[a-z\x{00a1}-\x{ffff}0-9]
+ 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 insensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case insensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case insensitive)
-
matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
Match a single character present in the list below
[a-z\x{00a1}-\x{ffff}0-9]
+ 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 insensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case insensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case insensitive)
Non-capturing group
(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}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 4610 (2E16 or 568) literally (case insensitive)
Non-capturing group
(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
Match a single character present in the list below
[a-z\x{00a1}-\x{ffff}0-9]
+ 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 insensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case insensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case insensitive)
-
matches the character - with index 4510 (2D16 or 558) literally (case insensitive)
Match a single character present in the list below
[a-z\x{00a1}-\x{ffff}0-9]
+ 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 insensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case insensitive)
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case insensitive)
Non-capturing group
(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,}))
\. matches the character . with index 4610 (2E16 or 568) literally (case insensitive)
Non-capturing group
(?:[a-z\x{00a1}-\x{ffff}]{2,})
Match a single character present in the list below
[a-z\x{00a1}-\x{ffff}]
{2,} matches the previous token between 2 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 insensitive)
\x{00a1}-\x{ffff} matches a single character in the range between ¡ (index 161) and ￿ (index 65535) (case insensitive)
Non-capturing group
(?::\d{2,5})?
? 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 insensitive)
\d
matches a digit (equivalent to [0-9])
{2,5} matches the previous token between 2 and 5 times, as many times as possible, giving back as needed (greedy)
Non-capturing group
(?:\/[^\s]*)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
\/ matches the character / with index 4710 (2F16 or 578) literally (case insensitive)
Match a single character not present in the list below
[^\s]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\s matches any whitespace character (equivalent to [\r\n\t\f\v ])
\b assert position at a word boundary: (^\w|\w$|\W\w|\w\W)
Global pattern flags
g modifier: global. All matches (don't return after first match)
i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
gi

Test String