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

/
/
ig

Test String

Code Generator

Language

Generated Code

const regex = /\b(?:(?:ht|f)tp(?:s?)\:\/\/|~\/|\/)?(?:\w+:\w+@)?((?:(?:[-\w\d{1-3}]+\.)+(?:com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|edu|co\.uk|ac\.uk|it|fr|tv|museum|asia|local|travel|[a-z]{2}))|((\b25[0-5]\b|\b[2][0-4][0-9]\b|\b[0-1]?[0-9]?[0-9]\b)(\.(\b25[0-5]\b|\b[2][0-4][0-9]\b|\b[0-1]?[0-9]?[0-9]\b)){3}))(?::[\d]{1,5})?(?:(?:(?:\/(?:[-\w~!$+|.,=]|%[a-f\d]{2})+)+|\/)+|\?|#)?(?:(?:\?(?:[-\w~!$+|.,*:]|%[a-f\d{2}])+=?(?:[-\w~!$+|.,*:=]|%[a-f\d]{2})*)(?:&(?:[-\w~!$+|.,*:]|%[a-f\d{2}])+=?(?:[-\w~!$+|.,*:=]|%[a-f\d]{2})*)*)*(?:#(?:[-\w~!$ |\/.,*:;=]|%[a-f\d]{2})*)?\b/ig; // Alternative syntax using RegExp constructor // const regex = new RegExp('\\b(?:(?:ht|f)tp(?:s?)\\:\\\/\\\/|~\\\/|\\\/)?(?:\\w+:\\w+@)?((?:(?:[-\\w\\d{1-3}]+\\.)+(?:com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|edu|co\\.uk|ac\\.uk|it|fr|tv|museum|asia|local|travel|[a-z]{2}))|((\\b25[0-5]\\b|\\b[2][0-4][0-9]\\b|\\b[0-1]?[0-9]?[0-9]\\b)(\\.(\\b25[0-5]\\b|\\b[2][0-4][0-9]\\b|\\b[0-1]?[0-9]?[0-9]\\b)){3}))(?::[\\d]{1,5})?(?:(?:(?:\\\/(?:[-\\w~!$+|.,=]|%[a-f\\d]{2})+)+|\\\/)+|\\?|#)?(?:(?:\\?(?:[-\\w~!$+|.,*:]|%[a-f\\d{2}])+=?(?:[-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)(?:&(?:[-\\w~!$+|.,*:]|%[a-f\\d{2}])+=?(?:[-\\w~!$+|.,*:=]|%[a-f\\d]{2})*)*)*(?:#(?:[-\\w~!$ |\\\/.,*:;=]|%[a-f\\d]{2})*)?\\b', 'ig') const str = `# valid http://www.google.com ftp://example.com google.com a.google.com a.google.com/b/~user http://www.google.com/~user www.google.com/sdfa/asdf?f93+3234 accounts.google.com valid.domain.com/foasdf/~23423lj accounts.google.com/login?res=sdfs sdf accounts.google.com you.name you.name/~joe google.com/+joe https://joe:test@test.com # partial http://joe@test.com # invalid not: ftp://example something.asfdasjdlf; abc.def@#\$90fai something.like.this abc.def `; // 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