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

Code Generator

Language

Generated Code

const regex = /<style[^>]*>([^<]+)?<[\s\/]+style>/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('<style[^>]*>([^<]+)?<[\\s\\\/]+style>', 'gm') const str = `<head> <meta property="og:locale" content="en_US" /> <meta property="og:type" content="website" /> <style>html{line-height:1.15;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%;}</style> <link rel='dns-prefetch' href='//js.stripe.com' /> <style id="pf-used-css">button,hr,input{overflow:visible;}[type="checkbox"],[type="radio"],legend{box-sizing:border-box;padding:0;}html{line-height:1.15;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%;}body,h1,h2,h3,h4,h5,h6{margin:0;}article,aside,details,figcaption,figure,footer,header,main,menu,nav,section{display:block;}hr{background-image:url("data:image/svg+xml;charset=utf-8,<svg viewBox=\\"0 0 50 50\\" height=\\"24\\" width=\\"24\\" xmlns=\\"http://www.w3.org/2000/svg\\" fill=\\"%23B0B0B0\\"><path d=\\"M 9.15625 6.3125 L 6.3125 9.15625 L 22.15625 25 L 6.21875 40.96875 L 9.03125 43.78125 L 25 27.84375 L 40.9375 43.78125 L 43.78125 40.9375 L 27.84375 25 L 43.6875 9.15625 L 40.84375 6.3125 L 25 22.15625 L 9.15625 6.3125 z\\"/></svg>");}.swal-label-required{display:inline-block;position:relative;right:9999px;margin-left:10px;}</style> <style>html{line-height:1.15;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%;}</style> </head> <body>`; // 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