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

r"
"
gm

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?:https?:\\/\\/|\\/\\/)?(?:(?:www\\.|m\\.)?youtube(?:-nocookie)?\\.com\\/(?:(?:vi?|e|embed)\\/([\\w-]{11})|(?:watch|embed|attribution_link)?\\?\\S*?(?:(?<=\\?v=|&v=)|(?<=\\?vi=|&vi=))([\\w-]{11}))|youtu\\.be\\/(?:([\\w-]{11})(?!\\S*v=)|\\S*?(?:&v=|\\?v=)([\\w-]{11})))(?:[^\\w-]\\S*)?$"; final String string = "My tests\n\n" + "https://www.youtube.com/watch?t=10&v=m_KBvP0_8Tc&sss\n\n" + "https://youtu.be/watch?v=e70VCVR-oQo&v=asdssssssss\n\n" + "https://youtu.be/watch?t=10s&v=e70VCVR-oQo\n\n" + "https://youtu.be/aaaaaaaaaaa?t=10&v=e70VCVR-oQo&v=asdssssssss\n\n" + "https://www.youtube.com/watch?t=10&v=e70VCVR-oQo&v=asdssssssss\n\n" + "http://youtu.be/oTJRivZTMLs&t=10\n\n\n\n" + "List of YouTube links I found online\n\n" + "//www.youtube-nocookie.com/embed/up_lNV-yoK4?rel=0\n\n" + "https://www.youtube.com/embed/XNHjiJVz0ks?feature%3Doembed&amp;display_name=YouTube&amp;url=https://www.youtube.com/watch?v%3DXNHjiJVz0ks&amp;image=https://i.ytimg.com/vi/XNHjiJVz0ks\n\n" + "http://www.youtube.com/watch?v=-wtIMTCHWuI/vi/XNHjiJVz0ks\n\n" + "https://www.youtube.com/watch?v=m_KBvP0_8Tc&v=asdssssssss\n\n" + "https://m.youtube.com/watch?v=m_kbvp0_8tc\n\n" + "http://www.youtube.com/v/-wtIMTCHWuI?version=3&autohide=1\n\n" + "http://youtu.be/-wtIMTCHWuI\n\n" + "https://www.youtube.com/watch?v=m_KBvP0_8Tc\n\n" + "https://www.youtube.com/watch?v=yZv2daTWRZU&feature=em-uploademail\n\n" + "https://www.youtube.com/watch?v=0zM3nApSvMg&feature=feedrec_grec_index\n\n" + "https://www.youtube.com/v/0zM3nApSvMg?fs=1&amp;hl=en_US&amp;rel=0\n\n" + "https://www.youtube.com/watch?v=0zM3nApSvMg#t=0m10s\n\n" + "https://www.youtube.com/embed/0zM3nApSvMg?rel=0\n\n" + "//www.youtube-nocookie.com/embed/up_lNV-yoK4?rel=0\n\n" + "https://www.youtube-nocookie.com/embed/up_lNV-yoK4?rel=0\n\n" + "http://www.youtube.com/watch?v=cKZDdG9FTKY&feature=channel\n\n" + "http://www.youtube.com/watch?v=yZ-K7nCVnBI&playnext_from=TL&videos=osPknwzXEas&feature=sub\n\n" + "http://www.youtube.com/watch?v=6dwqZw0j_jY&feature=youtu.be\n\n" + "http://www.youtube.com/embed/nas1rJpm7wY?rel=0\n\n" + "https://www.youtube.com/watch?v=peFZbP64dsU\n\n" + "http://youtube.com/v/peFZbP64dsU?feature=youtube_gdata_player\n\n" + "http://youtube.com/?v=dQw4w9WgXcQ&feature=youtube_gdata_player\n\n" + "http://www.youtube.com/watch?v=dQw4w9WgXcQ&feature=youtube_gdata_player\n\n" + "http://youtube.com/?vi=dQw4w9WgXcQ&feature=youtube_gdata_player\n\n" + "http://youtube.com/watch?v=dQw4w9WgXcQ&feature=youtube_gdata_player\n\n" + "http://youtube.com/watch?vi=dQw4w9WgXcQ&feature=youtube_gdata_player\n\n" + "http://youtube.com/vi/dQw4w9WgXcQ?feature=youtube_gdata_player\n\n" + "http://youtu.be/dQw4w9WgXcQ?feature=youtube_gdata_player\n\n" + "https://www.youtube.com/watch?v=ishbTyLs6ps&list=PLGup6kBfcU7Le5laEaCLgTKtlDcxMqGxZ&index=106&shuffle=2655\n\n" + "http://www.youtube.com/v/0zM3nApSvMg?fs=1&hl=en_US&rel=0\n\n" + "http://www.youtube.com/watch?v=0zM3nApSvMg&feature=feedrec_grec_index\n\n" + "http://www.youtube.com/watch?v=0zM3nApSvMg#t=0m10s\n\n" + "http://www.youtube.com/embed/dQw4w9WgXcQ\n\n" + "http://www.youtube.com/v/dQw4w9WgXcQ\n\n" + "http://www.youtube.com/e/dQw4w9WgXcQ\n\n" + "http://www.youtube.com/?v=dQw4w9WgXcQ\n\n" + "http://www.youtube.com/watch?feature=player_embedded&v=dQw4w9WgXcQ\n\n" + "http://www.youtube.com/?feature=player_embedded&v=dQw4w9WgXcQ\n\n" + "http://www.youtube-nocookie.com/v/6L3ZvIMwZFM?version=3&hl=en_US&rel=0\n\n" + "https://youtu.be/oTJRivZTMLs?list=PLToa5JuFMsXTNkrLJbRlB--76IAOjRM9b\n\n" + "http://www.youtube.com/watch?v=oTJRivZTMLs&feature=youtu.be\n\n" + "http://youtu.be/oTJRivZTMLs&feature=channel\n\n" + "http://www.youtube.com/embed/oTJRivZTMLs?rel=0\n\n" + "http://youtube.com/vi/oTJRivZTMLs&feature=channel\n\n" + "http://youtube.com/?v=oTJRivZTMLs&feature=channel\n\n" + "http://youtube.com/?feature=channel&v=oTJRivZTMLs\n\n" + "http://youtube.com/?vi=oTJRivZTMLs&feature=channel\n\n" + "http://youtube.com/watch?v=oTJRivZTMLs&feature=channel\n\n" + "http://youtube.com/watch?vi=oTJRivZTMLs&feature=channel"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html