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
Processing...

Test String

Code Generator

Language

Generated Code

const regex = /(https?)?(:\/\/)?(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()!@:%_\+.~#?&\/\/=]*)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(https?)?(:\\\/\\\/)?(www\\.)?[-a-zA-Z0-9@:%._\\+~#=]{1,256}\\.[a-zA-Z0-9()]{1,6}\\b([-a-zA-Z0-9()!@:%_\\+.~#?&\\\/\\\/=]*)', 'gm') const str = `http://bbc.co.uk/metus/aenean/fermentum.jpg?ipsum=massa&integer=id&a=lobortis&nibh=convallis&in=tortor&quis=risus&justo=dapibus&maecenas=augue&rhoncus=vel&aliquam=accumsan&lacus=tellus&morbi=nisi&quis=eu&tortor=orci&id=mauris&nulla=lacinia&ultrices=sapien&aliquet=quis&maecenas=libero&leo=nullam&odio=sit&condimentum=amet&id=turpis&luctus=elementum&nec=ligula edublogs.org/augue/luctus.html?feugiat=pellentesque&et=eget&eros=nunc&vestibulum=donec&ac=quis&est=orci&lacinia=eget&nisi=orci&venenatis=vehicula&tristique=condimentum&fusce=curabitur&congue=in&diam=libero&id=ut&ornare=massa&imperdiet=volutpat&sapien=convallis&urna=morbi&pretium=odio&nisl=odio&ut=elementum&volutpat=eu&sapien=interdum&arcu=eu&sed=tincidunt&augue=in&aliquam=leo&erat=maecenas&volutpat=pulvinar&in=lobortis&congue=est&etiam=phasellus&justo=sit /nunc/commodo/placerat/praesent/blandit.aspx?mauris=rutrum&vulputate=at&elementum=lorem&nullam=integer&varius=tincidunt&nulla=ante&facilisi=vel&cras=ipsum&non=praesent&velit=blandit&nec=lacinia&nisi=erat&vulputate=vestibulum&nonummy=sed&maecenas=magna&tincidunt=at&lacus=nunc&at=commodo&velit=placerat&vivamus=praesent&vel=blandit&nulla=nam&eget=nulla&eros=integer&elementum=pede&pellentesque=justo&quisque=lacinia&porta=eget&volutpat=tincidunt&erat=eget&quisque=tempus&erat=vel&eros=pede&viverra=morbi&eget=porttitor&congue=lorem&eget=id&semper=ligula&rutrum=suspendisse&nulla=ornare&nunc=consequat ?est=molestie&donec=lorem&odio=quisque&justo=ut&sollicitudin=erat&ut=curabitur&suscipit=gravida&a=nisi&feugiat=at&et=nibh&eros=in&vestibulum=hac&ac=habitasse&est=platea&lacinia=dictumst&nisi=aliquam&venenatis=augue&tristique=quam&fusce=sollicitudin&congue=vitae&diam=consectetuer&id=eget&ornare=rutrum&imperdiet=at&sapien=lorem&urna=integer espn.com https://espn.com www.espn.com https://www.espn.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