Regular Expressions 101

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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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

const regex = /(.*)(GET|POST|HEAD) ([^? ]+)\?([^\"]+)(\".*)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(.*)(GET|POST|HEAD) ([^? ]+)\\?([^\\"]+)(\\".*)', 'gm') const str = `2024/11/15 13:10:11 [error] 4080#4080: *260309 connect() failed (111: Connection refused) while connecting to upstream, client: 210.54.88.72, server: mpos.mintpayments.com, request: "GET /payment-mint/cnpPayments/v1/publicKeys?callback=jQuery360014295356911736334_1731369073329&X-Signature=plkb810sFSSSIbASLb818BMXxgtUM76QNvhI%252FBA%253D&X-Timestamp=1731368881376&X-ApiKey=CSSSAPXXXXXXPxmO7kjMi&X-CompanyToken=d1111e8lV1mpvljiCD2zRgEEU121p&_=1731369073330 HTTP/1.1", upstream: "https://10.20.3.59:28076//cnpPayments/v1/publicKeys?callback=jQuery360014295356911736334_17313690733...", host: "test.mintpayments.com", referrer: "https://vicky9.mintpayments.com/testing??asd"`; const subst = `$1$2 $3$5`; // The substituted value will be contained in the result variable const result = str.replace(regex, subst); console.log('Substitution result: ', result);

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions