Is Regex Cheatsheet free to use?

Yes, Regex Cheatsheet on DevHexLab is completely free. No login, no account, and no payment required.

Does Regex Cheatsheet upload my data to a server?

No. Regex Cheatsheet runs entirely in your browser using client-side JavaScript. Your data never leaves your device and is never sent to any server.

Can I use Regex Cheatsheet offline?

Yes. Once the page is loaded, Regex Cheatsheet works without an internet connection because all processing happens locally in your browser.

What category does Regex Cheatsheet belong to?

Regex Cheatsheet belongs to the "Developer Reference" category on DevHexLab. Searchable cheatsheets and quick-reference guides for the technologies developers reach for every day — HTTP status codes, HTML entities, Git commands, regex syntax, and more. Keep these references one tab away and stop Googling the same lookups over and over.

Regex Cheatsheet

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

regexcheatsheetreferencepatternguide

Live Regex Tester

Pattern

Test String

Highlighted Matches3 matches

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

Showing 56 of 56 entries

Character Classes

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`

Anchors

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'`

Quantifiers

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`

Groups & References

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`

Lookahead & Lookbehind

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'`

Flags

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`

Special Characters

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]`

Regex Cheatsheet is coming soon

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Learn more

Step-by-step guide

How to Use the Regex Cheat Sheet

Step-by-step guide to finding the right regular expression syntax for any matching task using the DevHexLab Regex Cheat Sheet.

In-depth article

Regex Cheatsheet: Every Pattern You Need for Regular Expressions

A practical reference for regular expression syntax. Covers character classes, quantifiers, anchors, groups, lookaheads, and common patterns with examples.

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