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Interactive regex cheatsheet where you can click patterns to test them live

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Pattern

Test String

Highlighted Matches3 matches

Hello 42 World 2024, regex is fun with 3 numbers!

Showing 56 of 56 entries

Pattern	Description	Example
`.`	Any character except newline	`c.t → cat, cot, cut`
`\w`	Word character: [a-zA-Z0-9_]	`\w+ → hello, foo_bar, abc123`
`\W`	Non-word character	`\W → space, !, @, #`
`\d`	Digit: [0-9]	`\d{3} → 123, 456, 789`
`\D`	Non-digit character	`\D+ → hello, foo!`
`\s`	Whitespace: space, tab, newline	`hello\sworld → hello world`
`\S`	Non-whitespace character	`\S+ → hello, world`
`[abc]`	Character in set a, b, or c	`[aeiou] → a, e, i, o, u`
`[^abc]`	Character not in set	`[^aeiou] → b, c, d, f`
`[a-z]`	Character in range a through z	`[a-z]+ → hello, world`
`[A-Z]`	Character in range A through Z	`[A-Z][a-z]+ → Hello, World`
`[0-9]`	Digit character (same as \d)	`[0-9]+ → 123, 4567`
`[a-zA-Z]`	Any letter (upper or lower)	`[a-zA-Z]+ → Hello, World`

Pattern	Description	Example
`^`	Start of string (or line in multiline mode)	`^hello → matches 'hello world' but not 'say hello'`
`$`	End of string (or line in multiline mode)	`world$ → matches 'hello world' but not 'worldwide'`
`\b`	Word boundary	`\bcat\b → matches 'cat' but not 'catch'`
`\B`	Non-word boundary	`\Bcat\B → matches 'scat' but not standalone 'cat'`
`\A`	Absolute start of string (not affected by multiline)	`\Ahello → 'hello world'`
`\Z`	Absolute end of string	`world\Z → 'hello world'`

Pattern	Description	Example
`*`	Zero or more of the preceding element	`ab*c → ac, abc, abbc, abbbc`
`+`	One or more of the preceding element	`ab+c → abc, abbc (not ac)`
`?`	Zero or one of the preceding element (optional)	`colou?r → color, colour`
`{n}`	Exactly n repetitions	`\d{4} → 2024, 1999`
`{n,}`	At least n repetitions	`\d{2,} → 12, 123, 1234`
`{n,m}`	Between n and m repetitions (inclusive)	`\d{2,4} → 12, 123, 1234`
`*?`	Lazy: zero or more (as few as possible)	`<.*?> → matches smallest <tag>`
`+?`	Lazy: one or more (as few as possible)	`<.+?> → matches smallest <a>`
`??`	Lazy: zero or one (prefer zero)	`colou??r → prefers 'color'`
`{n,m}?`	Lazy version of bounded quantifier	`\d{2,4}? → matches 2 digits preferably`

Pattern	Description	Example
`(abc)`	Capturing group: captures the match	`(\d{3})-(\d{4}) → captures area code and number`
`(?:abc)`	Non-capturing group: groups without capturing	`(?:foo\|bar)baz → foobaz, barbaz`
`(?<name>abc)`	Named capturing group	`(?<year>\d{4})-(?<month>\d{2})`
`\1, \2`	Backreference to captured group 1, 2, etc.	`(\w+)\s\1 → matches 'the the', 'foo foo'`
`\k<name>`	Backreference to named group	`(?<w>\w+)\s\k<w> → 'the the'`
`\|`	Alternation: matches either expression	`cat\|dog → cat, dog`

Pattern	Description	Example
`(?=abc)`	Positive lookahead: followed by abc	`\d+(?= dollars) → '100' in '100 dollars'`
`(?!abc)`	Negative lookahead: not followed by abc	`\d+(?! dollars) → '100' in '100 euros'`
`(?<=abc)`	Positive lookbehind: preceded by abc	`(?<=\$)\d+ → '100' in '$100'`
`(?<!abc)`	Negative lookbehind: not preceded by abc	`(?<!\$)\d+ → '100' in '100 items'`

Pattern	Description	Example
`g`	Global: find all matches (not just first)	`/\d+/g → finds all numbers in string`
`i`	Case-insensitive matching	`/hello/i → Hello, HELLO, hello`
`m`	Multiline: ^ and $ match start/end of each line	`/^foo/m → matches 'foo' on any line`
`s`	Dotall: . matches newline characters too	`/a.b/s → matches 'a\nb'`
`u`	Unicode: treat pattern as Unicode code points	`/\u{1F600}/u → matches emoji`
`y`	Sticky: match only from lastIndex position	`/foo/y → matches at exact position`
`d`	Indices: return start/end indices of matches	`/foo/d → returns index data`

Pattern	Description	Example
`\n`	Newline character	`line1\nline2`
`\t`	Tab character	`col1\tcol2`
`\r`	Carriage return	`line1\r\nline2`
`\0`	Null character	`data\0end`
`\uXXXX`	Unicode character by hex code point	`\u0041 → A`
`\xHH`	ASCII character by hex value	`\x41 → A`
`\\`	Literal backslash	`C:\\Users → C:\Users`
`\.`	Literal dot (escaping special char)	`example\.com → example.com`
`\(`	Literal parenthesis	`$hello$ → (hello)`
`\[`	Literal bracket	`\[0\] → [0]`

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