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

Generated Code

const regex = new RegExp('(https?://[-a-zA-Z0-9@:%._+~#=]{1,256}\\.[a-zA-Z0-9()]{1,6}[-a-zA-Z0-9()@:%_+.~#?&/=]*/?([-a-zA-Z0-9()@%_+~#?&/=]|\\b))', 'gm') const str = `Visit https://example.com for more information. Check out https://github.com/user/repo, it's really good. The API endpoint is https://api.service.com/v1/data; use it carefully. Go to https://example.com: it has everything you need. See https://docs.example.com? It explains the process. Try https://example.com! It's amazing. The site (https://example.com) is down for maintenance. Links like https://example.com are common in emails. Visit https://example.com/path/file.pdf and download it. The URL https://example.com/api?key=123 returns JSON data. Check https://example.com, https://test.org, and https://demo.net. Go to https://example.com... wait, that's the wrong link. The website https://example.com-- actually, never mind. Visit https://example.com/path?q=value&r=2 for the search results. See https://example.com/file.html, then click the button. The documentation at https://docs.example.com; section 4.2 explains it. Try https://example.com:8080/api/v1/users for user data. Links: https://example.com, https://test.org; both are useful. Go to https://example.com/path/to/resource, download the file. The URL https://example.com/path#section contains the answer. Visit https://example.com/very/long/path/here for details. Check https://sub.domain.example.com for subdomain content. The site https://example.com/path.with.dots has interesting content. Go to https://example.com/path-with-dashes?, it's well organized. See https://example.com/path_with_underscores for more info. The endpoint https://api.example.com/v2/data?format=json returns data. Visit https://example.com/file.tar.gz to download the archive. Check https://example.com/path?param=value.with.dots for configuration. The URL https://192.168.1.1:8080 is for local testing. Go to https://example.com/path/ (note the trailing slash).`; // 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