Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gmi

Test String

Code Generator

Language

Generated Code

re = /(?:"?[a-z0-9_\-]{0,256}(?:key|secret|token)[a-z0-9_\-]{0,256}"?\s{0,10}(?::|=)\s{0,10}\"?(?!null|true|false)([a-z0-9+_:\.\-\/]{1,1024})|"Authorization":"[a-z0-9+:_\-\/]{1,1024}\s(.{1,1024}?(?<!\\)(?=")))/mi str = '{"secret":"asdfffasdf","headers":{"uri_1":"https://www.api.example.com/api/?count=433&apiKey=DD238B9E4369248330EFBB58D6B1431AFB03C8E1D&debug=true","uri_2":"https://www.api.example.com/api/?secret=5ZQD9jhp51qVE5199xU4zj2X2wSPGwNpDub2CiSJO3i","uri_3":"https://www.api.example.com/api/?token=CE362359AAFCB1F8C5BAF4692FD67C18&debug=true","uri_4":"https://www.api.example.com/api/?secret_token=4DA9155E26A75C6D83E208FF518EAFE4&debug=true","uri_5":"https://www.api.example.com/api/?count=433&key=NeRPfka6TETPfHvNoLP4WPBxhhsrOzOh9HyC&debug=true","uri_6":"https://www.api.example.com/api/?apitoken=jq3PGKQDhKjJVo33hRVPK36q0r9-asdf_asdf","uri_7":"https://www.api.example.com/api/?api_key=7119971F47DE25C366F9AB506A1BFD&debug=true","uri_8":"https://www.api.example.com/api/?secret-key=93326A9B41C3DF94BED6E4C9DC524A4F6","uri_9":"https://www.api.example.com/api/?client_secret=6C844DE60C4104936541D4EAB32404DA&debug=true","uri_10":"https://www.api.example.com/api/?count=433&list=daisy&test=true&api_token=lYb6y4GYvFjmW0F8bGAXtcogmkRGa3hkgph530&debug=true","uri_11":"https://www.api.example.com/api/?count=433&api_secret=lYb6y4GYvFjmW0F8bGAXtcogmkRGa3hkgph530&debug=true","uri_12":"https://www.api.example.com/api/?token-pin=8433","uri_13":"https://www.api.example.com/api/?key=4343","uri_14":"https://www.api.example.com/api/?secret-pin=32211190332933","auth_0":{"Authorization":"Digest username=username, asfsfsf=\\"dsffadf\\",\\nasfsfsf=\\"dsffadf\\",\\nasfsfsf=\\"dsffadf\\",\\nasdfsf=asdfsdf"},"auth_1":{"Authorization":"Bearer dasd/4rV4MjOdjA3pu9rJ5qc9RKuCoAO8UaxuWUGXUtuzRJKdRTvKMVe3dJ9FN1SyF9n=="},"auth_2":{"Authorization":"App D4D0BB1B2F12B5E97405C764CA45F"},"auth_3":{"Authorization":"IPSO dasd+F51B63334AD3520894712D15D8F1105ED3DD"},"auth_4":{"Authorization":"Key hJdilwrzM9616MJsDGBiK4qjeJFYB0zmHPxYNUrn8D54ycAN7gwedqHt0UiCWTb"},"auth_5":{"Authorization":"Digest username=username, oauth=\\"hhasjjjd+ddad\\",\\nnonce=\\"dsffadf\\",\\nhash=\\"ef05bc-89c2\\",\\nclient=myapp"},"auth_6":{"Authorization":"Digest username=\\"6551156d‑569c‑4b7d‑945f‑310ff10943c5\\", realm=\\"bob@contoso.com\\", qop=auth, algorithm=MD5-sess, uri=\\"sip:bob@contoso.com;gruu;opaque=app:conf:focus:id:854T0R7G\\", nonce=\\"h8A4ZW22ygGZozIIGZcb43waVMEM6Gq\\", nc=1, cnonce=\\"\\", opaque=\\"0C1D4536\\", response=\\"b4543cd4d6a923b4ab4fd4583af48f0e\\""},"auth_7":{"Authorization":"Digest username=\\"6551156d‑569c‑4b7d‑945f‑310ff10943c5\\",\\n realm=\\"bob@contoso.com\\",\\n qop=auth,\\n algorithm=MD5-sess,\\n uri=\\"sip:bob@contoso.com;gruu;opaque=app:conf:focus:id:854T0R7G\\",\\n nonce=\\"h8A4ZW22ygGZozIIGZcb43waVMEM6Gq\\",\\n nc=1, cnonce=\\"\\",\\n opaque=\\"0C1D4536\\",\\n response=\\"b4543cd4d6a923b4ab4fd4583af48f0e\\""},"apiId":null,"apiId_2":null,"apiKey4":12345689994,"apiKey5":"123344555",apiKey":null,"apiKey2":null,"apiKey3":"null"},"multiValueHeaders":{"Accept":["*/*"],"Accept-Encoding":["gzip, deflate, br"],"Cache-Control":["no-cache"],"Host":["myapi.api.example.com"],"Postman-Token":["86071fc6-35da-4ff5-8eb5-d44ce06e3eed"],"User-Agent":["PostmanRuntime/7.31.1"],"X-Amzn-Trace-Id":["Root=1-6428887b-15fa842f16c1eeaf5d812345"],"X-Forwarded-For":["10.61.41.39"],"X-Forwarded-Port":["443"],"X-Forwarded-Proto":["https"],"Client-Secret":["451234567890123456","90123456789012345","e3bc8a2051bae92cc32",8123456789012345678,"ed1234567890ca1234"],"Client-Token":["awbu+d4Tey28-32ntRW3X",82340514553298753123456,"hw_538291-ec0a91-123456"]}} ' # Print the match result str.scan(re) do |match| puts match.to_s end

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html