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 = /^(?P<date>\d{4}-\d+-\d+)\s+(?P<time>\d+:\d+:\d+)\s+(?P<ip>\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})\s+(?P<method>\w+)\s+(?P<uri>\/.*)\s+(?P<status>\d+)\s+(?P<bytes>\d+)\s+(?P<referer>\".*\")\s+(?P<useragent>\".*\")\s+(?P<cookie>\".*\")\s+(?P<custom>\".*\")\s+(?P<ghostip>\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3})\s+(?P<cache>\d)\s+(?P<wafinfo>\".*\")$/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^(?P<date>\\d{4}-\\d+-\\d+)\\s+(?P<time>\\d+:\\d+:\\d+)\\s+(?P<ip>\\d{1,3}.\\d{1,3}.\\d{1,3}.\\d{1,3})\\s+(?P<method>\\w+)\\s+(?P<uri>\\\/.*)\\s+(?P<status>\\d+)\\s+(?P<bytes>\\d+)\\s+(?P<referer>\\".*\\")\\s+(?P<useragent>\\".*\\")\\s+(?P<cookie>\\".*\\")\\s+(?P<custom>\\".*\\")\\s+(?P<ghostip>\\d{1,3}.\\d{1,3}.\\d{1,3}.\\d{1,3})\\s+(?P<cache>\\d)\\s+(?P<wafinfo>\\".*\\")$', 'gm') const str = `#Fields: date time cs-ip cs-method cs-uri sc-status sc-bytes time-taken cs(Referer) cs(User-Agent) cs(Cookie) x-custom ghostip cache_status x-wafinfo 2023-11-17 07:33:55 217.165.96.151 GET /www.argos.co.uk/assets/common/polyfills/3.0.17/polyfills-request-idle-callback.min.js 200 1400 22 "https://www.argos.co.uk/product/4660185?cjdata=MXxOfDB8WXww&\$ja=tsid%3A11674%7Cprd%3A100072047&utm_source=Skimlinks&utm_medium=affiliates&utm_campaign=Argos+Deep+Generator+AID-+DO+NOT+CHANGE&utm_content=10830324&utm_custom1=100072047&utm_custom2=Other&cmpid=cojun&cjevent=a61535ab851b11ee8392ee230a1cb82a&dclid=CLv4hcTCyoIDFe9C9ggdWDMACA" "Mozilla/5.0 (iPhone; CPU iPhone OS 16_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Mobile/15E148 Safari/604.1" "akaas_arg_uk_global=1707982435~rv=34~id=e302e31ea1f9450e13700fd5beee9884" "-" 2.21.231.4 1 "1111_3104||" 2023-11-17 07:33:55 217.165.96.151 GET /www.argos.co.uk/assets/common/vendor/5.0.17/commonvendor-react.min.js 200 56746 23 "https://www.argos.co.uk/product/4660185?cjdata=MXxOfDB8WXww&\$ja=tsid%3A11674%7Cprd%3A100072047&utm_source=Skimlinks&utm_medium=affiliates&utm_campaign=Argos+Deep+Generator+AID-+DO+NOT+CHANGE&utm_content=10830324&utm_custom1=100072047&utm_custom2=Other&cmpid=cojun&cjevent=a61535ab851b11ee8392ee230a1cb82a&dclid=CLv4hcTCyoIDFe9C9ggdWDMACA" "Mozilla/5.0 (iPhone; CPU iPhone OS 16_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Mobile/15E148 Safari/604.1" "akaas_arg_uk_global=1707982435~rv=34~id=e302e31ea1f9450e13700fd5beee9884" "-" 2.21.231.4 1 "1111_3104||"`; // 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