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

/
/
gim

Test String

Code Generator

Language

Generated Code

const regex = /(?<FULLREQUEST>^(?<HOST>(?<PROTOCOL>(?:http)?s?:?\/\/)(?<DOMAIN>[^\/]+\/)|(?<RELATIVE>(?:\.*\/?)+))(?<PATH>[^\s]+\/)?(?<FILENAME>(?:(?<NAME>[^\/\s\.\?\#]+?)?(?<EXT>\.[^\s\?\#]*)?|(?:\/[^\/\s\?\#]+?)))(?<QUERYSTRING>\?[^\s\#]+)?(?<ANCHOR>\#\S+)?$)/gim; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?<FULLREQUEST>^(?<HOST>(?<PROTOCOL>(?:http)?s?:?\\\/\\\/)(?<DOMAIN>[^\\\/]+\\\/)|(?<RELATIVE>(?:\\.*\\\/?)+))(?<PATH>[^\\s]+\\\/)?(?<FILENAME>(?:(?<NAME>[^\\\/\\s\\.\\?\\#]+?)?(?<EXT>\\.[^\\s\\?\\#]*)?|(?:\\\/[^\\\/\\s\\?\\#]+?)))(?<QUERYSTRING>\\?[^\\s\\#]+)?(?<ANCHOR>\\#\\S+)?$)', 'gim') const str = `Domain Name Root https://www.domain.com/ https://www.domain.com/?with=queryString https://www.domain.com/#withAnchor https://www.domain.com/?with=queryString#andAnchor Full Domain Name With File https://www.domain.com/with-file https://www.domain.com/with-file?with=queryString https://www.domain.com/with-file#withAnchor https://www.domain.com/with-file?with=queryString#andAnchor Full Domain Name With File With Extension https://www.domain.com/file-with.ext https://www.domain.com/file-with.ext?with=queryString https://www.domain.com/file-with.ext#withAnchor https://www.domain.com/file-with.ext?with=queryString#andAnchor Full Domain Name With Path to File https://www.domain.com/some-path/to/a/file https://www.domain.com/some-path/to/a/file?with=queryString https://www.domain.com/some-path/to/a/file#withAnchor https://www.domain.com/some-path/to/a/file?with=queryString#andAnchor Full Domain Name With Path to File With Extension https://www.domain.com/some-path/to/a/file-with.ext https://www.domain.com/some-path/to/a/file-with.ext?with=queryString https://www.domain.com/some-path/to/a/file-with.ext https://www.domain.com/some-path/to/a/file-with.ext?with=queryString#andAnchor Dynamic Protocol Full Domain //www.domain.com/ //www.domain.com/?with=queryString //www.domain.com/#withAnchor //www.domain.com/?with=queryString#andAnchor Dynamic Protocol (Full Domain) to File //www.domain.com/with-file //www.domain.com/with-file?with=queryString //www.domain.com/with-file#withAnchor //www.domain.com/with-file?with=queryString#andAnchor Dynamic Protocol (Full Domain) to File With Extension //www.domain.com/with-file-with.ext //www.domain.com/with-file-with.ext?with=queryString //www.domain.com/with-file-with.ext#withAnchor //www.domain.com/with-file-with.ext?with=queryString#andAnchor Dynamic Protocol (Full Domain), Path Leading to File //www.domain.com/with/path/to/file //www.domain.com/with/path/to/file?with=queryString //www.domain.com/with/path/to/file#withAnchor //www.domain.com/with/path/to/file?with=queryString#andAnchor Dynamic Protocol (Full Domain), Path Leading to File With Extension //www.domain.com/with/path/to/file-with.ext //www.domain.com/with/path/to/file-with.ext?with=queryString //www.domain.com/with/path/to/file-with.ext#withAnchor //www.domain.com/with/path/to/file-with.ext?with=queryString#andAnchor Root Relative File /some-root-file /some-root-file?with=queryString /some-root-file#withAnchor /some-root-file?with=queryString#andAnchor Root Relative File With Extension /root-file-with.ext /root-file-with.ext?with=queryString /root-file-with.ext#withAnchor /root-file-with.ext?with=queryString#andAnchor Root Path to File /some-root-path/to/a/file /some-root-path/to/a/file?with=queryString /some-root-path/to/a/file#withAnchor /some-root-path/to/a/file?with=queryString#andAnchor Root Path to File With Extension /some-root-path/to/a/file-with.ext /some-root-path/to/a/file-with.ext?with=queryString /some-root-path/to/a/file-with.ext#withAnchor /some-root-path/to/a/file-with.ext?with=queryString#andAnchor Relative (Same As Requestor) File ./relative-to-requester-file ./relative-to-requester-file?with=queryString ./relative-to-requester-file#withAnchor ./relative-to-requester-file?with=queryString#andAnchor Relative (Same As Requestor) File With Extension ./relative-to-requester-file-with.ext ./relative-to-requester-file-with.ext?with=queryString ./relative-to-requester-file-with.ext#withAnchor ./relative-to-requester-file-with.ext?with=queryString#andAnchor Relative (Same As Requestor) Path To File ./relative-to-requester-path/to/a/file ./relative-to-requester-path/to/a/file?with=queryString ./relative-to-requester-path/to/a/file#withAnchor ./relative-to-requester-path/to/a/file?with=queryString#andAnchor Relative (Same As Requestor) Path To File With Extension ./relative-to-requester-path/to/a/file-with.ext ./relative-to-requester-path/to/a/file-with.ext?with=queryString ./relative-to-requester-path/to/a/file-with.ext#withAnchor ./relative-to-requester-path/to/a/file-with.ext?with=queryString#andAnchor Relative (Above Requestor) File ../relative-file-up ../relative-file-up?with=queryString ../relative-file-up#withAnchor ../relative-file-up?with=queryString#andAnchor Relative (Above Requestor) File With Extension ../relative-file-up-with.ext ../relative-file-up-with.ext?with=queryString ../relative-file-up-with.ext#withAnchor ../relative-file-up-with.ext?with=queryString#andAnchor Relative (two Above Requestor) File ../../relative-file-two-up ../../relative-file-two-up?with=queryString ../../relative-file-two-up#withAnchor ../../relative-file-two-up?with=queryString#andAnchor Relative (two Above Requestor) File With Extension ../../relative-file-two-up.ext ../../relative-file-two-up.ext?with=queryString ../../relative-file-two-up.ext#withAnchor ../../relative-file-two-up.ext?with=queryString#andAnchor Relative (n Above Requestor) File ../../../../../../../../relative-file-n-up ../../../../../../../../relative-file-n-up?with=queryString ../../../../../../../../relative-file-n-up#withAnchor ../../../../../../../../relative-file-n-up?with=queryString#andAnchor Relative Path (Above Requestor) to File ../relative-path/up/to/a/file ../relative-path/up/to/a/file?with=queryString ../relative-path/up/to/a/file#withAnchor ../relative-path/up/to/a/file?with=queryString#andAnchor Relative Path (Above Requestor) to File With Extension ../relative-path/up/to/a/file-with.ext ../relative-path/up/to/a/file-with.ext?with=queryString ../relative-path/up/to/a/file-with.ext#withAnchor ../relative-path/up/to/a/file-with.ext?with=queryString#andAnchor Relative Path (Two Above Requestor) to File ../../relative-path/two/up/to/a/file ../../relative-path/two/up/to/a/file?with=queryString ../../relative-path/two/up/to/a/file#withAnchor ../../relative-path/two/up/to/a/file?with=queryString#andAnchor Relative Path (Two Above Requestor) to File With Extension ../../relative-path/two/up/to/a/file-with.ext ../../relative-path/two/up/to/a/file-with.ext?with=queryString ../../relative-path/two/up/to/a/file-with.ext#withAnchor ../../relative-path/two/up/to/a/file-with.ext?with=queryString#andAnchor Relative Path (n Above Requestor) to File ../../../../../relative-path/n/up/to/a/file ../../../../../relative-path/n/up/to/a/file?with=queryString ../../../../../relative-path/n/up/to/a/file#withAnchor ../../../../../relative-path/n/up/to/a/file?with=queryString#andAnchor Relative Path (n Above Requestor) to File With Extension ../../../../../relative-path/n/up/to/a/file-with.ext ../../../../../relative-path/n/up/to/a/file-with.ext?with=queryString ../../../../../relative-path/n/up/to/a/file-with.ext#withAnchor ../../../../../relative-path/n/up/to/a/file-with.ext?with=queryString#andAnchor `; // 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