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:\/\/(?:web.archive.org\/web\/\d*(?:|if_)|archive.*\/.*\/)\/((?:https?:\/\/)?(?:[^@\n]+@)?(?:www\.)?([^:\/\n?]+)).*$
/
gm
https:
matches the characters https: 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)
Non-capturing group
(?:web.archive.org\/web\/\d*(?:|if_)|archive.*\/.*\/)
1st Alternative
web.archive.org\/web\/\d*(?:|if_)
web
matches the characters web literally (case sensitive)
. matches any character (except for line terminators)
archive
matches the characters archive literally (case sensitive)
. matches any character (except for line terminators)
org
matches the characters org literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
web
matches the characters web literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) 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)
Non-capturing group
(?:|if_)
1st Alternative null, matches any position
2nd Alternative
if_
if_
matches the characters if_ literally (case sensitive)
2nd Alternative
archive.*\/.*\/
archive
matches the characters archive literally (case sensitive)
.
matches any character (except for line terminators)
* 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 any character (except for line terminators)
* 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 character / with index 4710 (2F16 or 578) literally (case sensitive)
1st Capturing Group
((?:https?:\/\/)?(?:[^@\n]+@)?(?:www\.)?([^:\/\n?]+))
Non-capturing group
(?:https?:\/\/)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
http
matches the characters http literally (case sensitive)
s
matches the character s with index 11510 (7316 or 1638) 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)
Non-capturing group
(?:[^@\n]+@)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
Match a single character not present in the list below
[^@\n]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
@ matches the character @ with index 6410 (4016 or 1008) literally (case sensitive)
\n matches a line-feed (newline) character (ASCII 10)
@ matches the character @ with index 6410 (4016 or 1008) literally (case sensitive)
Non-capturing group
(?:www\.)?
? matches the previous token between zero and one times, as many times as possible, giving back as needed (greedy)
www
matches the characters www literally (case sensitive)
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
2nd Capturing Group
([^:\/\n?]+)
Match a single character not present in the list below
[^:\/\n?]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
: matches the character : with index 5810 (3A16 or 728) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
\n matches a line-feed (newline) character (ASCII 10)
? matches the character ? with index 6310 (3F16 or 778) literally (case sensitive)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
$ 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

Regex Debugger

Please wait while your expression is being debugged...