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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?i)(?=(\\d)\\d\\d([\\s\\-\\x{2013}\\x{2014}\\/]))(?<![\\d\\-\\x{2013}\\x{2014}%])(?!000|666|9\\d\\d|\\1{3}.\\1{2}.\\1{4}?|012.34.5678|123.45.6789|234.56.7890|098.76.5432|876.54.3210|078.05.1120|219.09.9999)\\d{3}\\2(?!00)\\d{2}\\2(?!0000)\\d{4}(?![\\d\\-\\x{2013}\\x{2014}%])(?!\\.(?:pdf|docx?|xlsx?|pptx?|zip|jpe?g|png|txt|log)\\b)"; final String string = "################\n" + "## Must match:\n" + "################\n\n" + "123-45-4891\n" + "098-18-6564\n" + "123-45-4848\n" + "702-02-0202\n" + "001-14-0004\n\n" + "009 95 8881\n" + "123-45-4891 is my ssn\n" + "my ssn is 123-45-4891\n" + "my ssn is 123-45-4891 ok?\n" + "my ssn is 123-45-4891.\n" + "123454891 is my ssn\n\n" + "123 45 4891 is my ssn\n" + "my ssn is 123 45 4891\n" + "my ssn is 123 45 4891 ok?\n" + "my ssn is 123 45 4891.\n" + "my ssn is:123-45-4891.\n" + "my ssn is:123 45 4891.\n" + "my ssn is:123454891.\n" + "ss#123-45-4891\n" + "ssn123-45-4891\n\n" + "# Space separator:\n" + "123 45 4891\n\n" + "# Emdash separator:\n" + "123–45–4891\n\n" + "# Endash separator:\n" + "123—45—4891\n\n" + "# Slash separator\n" + "123/45/4891\n\n" + "################\n" + "## Must not match:\n" + "################\n\n" + "# Unformatted SSN:\n" + "009958881\n" + "my ssn is 123454891\n" + "my ssn is 123454891 ok?\n" + "my ssn is 123454891.\n\n" + "# All-Zero sequence\n" + "231-84-0000\n" + "231-00-7289\n" + "000-87-7289\n" + "231 84 0000\n" + "231 00 7289\n" + "000 87 7289\n\n" + "# Starting with 9\n" + "908-78-0485\n" + "908 78 0485\n\n" + "# Starting with 666\n" + "666-78-0485\n\n" + "# Same number sequences:\n" + "222-22-2222\n" + "555-55-5555\n\n" + "# Ascending/Descending sequences:\n" + "123-45-6789\n" + "876-54-321\n\n" + "# Known invalidated SSN:\n" + "219-09-9999\n" + "078-05-1120\n\n" + "# File names with common extensions:\n" + "123-45-4891.pdf\n" + "123-45-4891.xlsx\n" + "Check the attachment: 123-45-4891.xls, then get back to me.\n" + "Check the attachment: 123-45-4891.jpeg, then get back to me.\n\n" + "# Extra digits:\n" + "1123-45-4891\n" + "123-45-48911\n\n" + "# Unsupported boundaries:\n" + "–123-45-4891\n" + "—123-45-4891\n" + "%123-45-4891\n" + "123-45-4891-\n" + "123-45-4891—\n" + "123-45-4891%\n" + "1-123-45-4891\n" + "123-45-4891-1\n\n" + "# Telephone\n" + "1-234-567-8901\n" + "1-234-567-8901\n" + "1-234-567-8901 \n" + "1 (234) 567-8901\n" + "12347658901\n\n" + "# Credit card \n" + "5500 0000 0000 0004\n" + "3400 0000 0000 009\n" + "3000 0000 0000 04\n" + "5500-1244-2232-0004\n" + "3400-1244-0000-009\n" + "3000-1244-1234-04\n\n" + "# Random Numbers\n" + "1234567890112371298739872891738912738937289d712897381297381927d3128937893d7218947d1892742189duc89789v127c897412987893c12893c79\n" + "122-426-389\n" + "187-5-43212\n" + "187-0-43212\n" + "2423-45-6789\n"; 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