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

/
/
si

Test String

Code Generator

Language

Generated Code

const regex = /^(get|post|head|options|put|delete|trace|connect) [\x09-\x0d -~]*? http\/(0\.9|1\.0|1\.1)|^http\/(0\.9|1\.0|1\.1) [1-5][0-9][0-9]/si; // Alternative syntax using RegExp constructor // const regex = new RegExp('^(get|post|head|options|put|delete|trace|connect) [\\x09-\\x0d -~]*? http\\\/(0\\.9|1\\.0|1\\.1)|^http\\\/(0\\.9|1\\.0|1\\.1) [1-5][0-9][0-9]', 'si') const str = `HTTP/1.1 206 Partial Content Server: nginx Date: Wed, 11 Nov 2015 03:56:37 GMT Content-Type: application/octet-stream Content-Length: 356602 Last-Modified: Sat, 09 May 2015 01:02:03 GMT Connection: keep-alive Cache-Control: no-store Pragma: no-cache Access-Control-Allow-Origin: * Access-Control-Expose-Headers: X-TCP-Info,X-Session-Info X-TCP-Info: h0=1468775468;h1=1393591241;h2=2806702307;h3=4238532199;h4=1088413687; X-Session-Info: addr=14.203.114.166;port=64848;argp=6.r_LuFhNjxnyyv1lFwH73LPg5P97q98pNwisQ1a9GcfM Content-Range: bytes 221217390-221573991/345312900 ...{moof....mfhd...........ctraf....tfhd... ............tfdt....... .tj\`...Asaiz........0....................................`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; if ((m = regex.exec(str)) !== null) { // 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