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

r"
"
gm

Test String

Code Generator

Generated Code

const regex = new RegExp('^_?[a-z0-9]+(?:[._+-][a-z0-9]+)*@(?!\\d+(?:\\.\\d+)*$)(?:\\w+(?:-\\w+)*\\.)+\\w{2,}$', 'gm') const str = `###################### Valid Emails ######################################################## ######################## German, Austrian, international ################################### janedoe@web.de jane.doe@web.de jdoe@web.de jane-doe@web.de jane@web.de doe@web.de janed@web.de doej@web.de jane_doe@web.de j.doe@web.de jane.d@web.de janedoe@t-online.de jane.doe@t-online.de jdoe@t-online.de jane-doe@t-online.de jane@t-online.de janed@t-online.de doej@t-online.de jane_doe@t-online.de j.doe@t-online.de jane.d@t-online.de janedoe@hotmail.de jane.doe@hotmail.de jdoe@hotmail.de jane-doe@hotmail.de janedoe@gmx.de jane.doe@gmx.de jdoe@gmx.de jane-doe@gmx.de jane.doe@post.at jane-doe@post.at janedoe@post.at jane@post.at john.doe@austrian.com horneaudrey@fulbright.at email@example.web ##################################################################################### ########################## Not valid email ########################################## .test@gmail.com -test@gmail.com t.-.est@gmail.com .test.@gmail.com test.@gmail.com test.@.gmail.com test@.gmail.com test@.gmail.com. test@gmail.com. "email"@example.com #@%^%#\$@#\$@#.com @example.com Joe Smith <email@example.com> email.example.com email@example@example.com .email@example.com email.@example.com email..email@example.com あいうえお@example.com email@example.com (Joe Smith) email@example email@-example.com email@111.222.333.44444 email@example..com Abc..123@example.com`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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