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

/
/
mg

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?:(?i)(?:https:|http:)?\/\/)?(?:(?i)(?:www\.youtube\.com\/(?:embed\/|watch\?v=)|youtu\.be\/|youtube\.googleapis\.com\/v\/)(?<YoutubeID>[a-z0-9-_]{11,12})|(?:vimeo\.com\/|player\.vimeo\.com\/video\/)(?<VimeoID>[0-9]+))"; string input = @"https://www.youtube.com/embed/123456789012 https://www.youTUbe.com/embed/123456789012 http://www.youtube.com/watch?v=My2FRPA3Gf8 htTp://www.youtube.com/watch?V=My2FRPA3Gf8 http://youtu.be/My2FRPA3Gf8 http://youTU.be/My2FRPA3Gf8 https://www.youtu.be/embed/123456789012 https://youtube.googleapis.com/v/123456789012 https://youtube.googleAPis.com/v/123456789012 https://youtube.googleapis.com/embed/123456789012 https://www.youtube.com/embed/123456789012 http://www.youtube.com/embed/123456789012 //www.youtube.com/embed/123456789012 www.youtube.com/embed/123456789012 http://vimeo.com/25451551 http://player.vimeo.com/video/25451551 https://player.vimeo.com/video/6969232737373733383782383273287328327342873 http://player.vimeo.com/video/6969 "; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx