Regex Cheatsheet

A complete JavaScript regex reference — anchors, classes, quantifiers, groups, flags, and common patterns.

Anchors

Pattern	Description	Example
`^`	Start of string (or line in multiline mode)	^Hello matches 'Hello world'
`$`	End of string (or line in multiline mode)	world$ matches 'Hello world'
`\b`	Word boundary	\bcat\b matches 'cat' but not 'scatter'
`\B`	Non-word boundary	\Bcat matches 'scatter'
`\A`	Start of string (not supported in JS — use ^)	Use ^ in JavaScript
`\Z`	End of string (not supported in JS — use $)	Use $ in JavaScript

Pattern	Description	Example
`.`	Any character except newline	a.c matches 'abc', 'a1c'
`\d`	Digit [0-9]	\d+ matches '123'
`\D`	Non-digit [^0-9]	\D+ matches 'abc'
`\w`	Word character [a-zA-Z0-9_]	\w+ matches 'hello_42'
`\W`	Non-word character	\W matches spaces and symbols
`\s`	Whitespace (space, tab, newline)	\s+ matches ' '
`\S`	Non-whitespace	\S+ matches 'hello'
`[abc]`	Character set — matches a, b, or c	[aeiou] matches vowels
`[^abc]`	Negated set — any character except a, b, or c	[^0-9] matches non-digits
`[a-z]`	Range — any lowercase letter	[a-zA-Z] matches any letter
`[\u0041-\u005A]`	Unicode range	Matches A-Z via Unicode

Pattern	Description	Example
`*`	Zero or more (greedy)	a* matches '', 'a', 'aaa'
`+`	One or more (greedy)	a+ matches 'a', 'aaa'
`?`	Zero or one (optional)	colou?r matches 'color' or 'colour'
`{n}`	Exactly n occurrences	\d{4} matches '2024'
`{n,}`	n or more occurrences	\d{2,} matches '12', '123'
`{n,m}`	Between n and m occurrences	\d{2,4} matches '12', '123', '1234'
`*?`	Zero or more (lazy)	<.*?> matches first tag only
`+?`	One or more (lazy)	Stops as early as possible
`??`	Zero or one (lazy)	Prefers zero match

Pattern	Description	Example
`(abc)`	Capturing group	(\d+) captures digits
`(?:abc)`	Non-capturing group	(?:abc)+ groups without capture
`(?<name>abc)`	Named capturing group	(?<year>\d{4})
`\1`	Backreference to group 1	(\w)\1 matches 'aa', 'bb'
`\k<name>`	Named backreference	\k<year> references named group
`(?=abc)`	Positive lookahead — followed by	\d(?=px) matches digit before 'px'
`(?!abc)`	Negative lookahead — not followed by	\d(?!px) matches digit not before 'px'
`(?<=abc)`	Positive lookbehind — preceded by	(?<=\$)\d+ matches digits after $
`(?<!abc)`	Negative lookbehind — not preceded by	(?<!\$)\d+ matches digits not after $
`a\|b`	Alternation — a or b	cat\|dog matches 'cat' or 'dog'

Pattern	Description	Example
`g`	Global — find all matches (not just first)	/a/g matches all 'a's
`i`	Case-insensitive matching	/hello/i matches 'HELLO'
`m`	Multiline — ^ and $ match line starts/ends	/^foo/m matches 'foo' at start of any line
`s`	Dotall — . matches newlines too	/a.b/s matches 'a\nb'
`u`	Unicode mode — enables full Unicode support	/\u{1F600}/u matches emoji
`y`	Sticky — match only from lastIndex position	Used with regex.lastIndex
`d`	Indices — include match start/end indices	ES2022: match.indices

Pattern	Description	Example
`\n`	Newline	Split on \n
`\r`	Carriage return	Windows line endings \r\n
`\t`	Tab character	Matches tab-separated values
`\0`	Null character	Binary data delimiter
`\uXXXX`	Unicode escape (4 hex digits)	\u0041 matches 'A'
`\u{XXXXX}`	Unicode escape (with u flag)	\u{1F600} matches emoji
`\xHH`	Hex escape (2 hex digits)	\x41 matches 'A'
`\\`	Literal backslash	Matches '\'
`\.`	Literal dot	version\.js matches 'version.js'

Pattern	Description	Example
`^[\w.-]+@[\w.-]+\.\w{2,}$`	Email address (basic)	user@example.com
`https?:\/\/[\w\-._~:/?#[\]@!$&'()*+,;=%]+`	URL (http/https)	https://example.com
`\b(?:\d{1,3}\.){3}\d{1,3}\b`	IPv4 address	192.168.1.1
`^\d{4}-\d{2}-\d{2}$`	ISO date (YYYY-MM-DD)	2024-03-15
`^#(?:[0-9a-fA-F]{3}\|[0-9a-fA-F]{6})$`	Hex color code	#4F46E5 or #f60
`^\+?[1-9]\d{1,14}$`	International phone (E.164)	+31612345678
`^[A-Z]{2}\d{2}[A-Z0-9]{4,}$`	IBAN (basic structure)	GB82WEST12345698765432
`^(?=.[a-z])(?=.[A-Z])(?=.*\d).{8,}$`	Strong password (8+ chars, upper, lower, digit)	Password1
`^\d{5}(?:-\d{4})?$`	US ZIP code	12345 or 12345-6789
`[^\x00-\x7F]`	Non-ASCII characters	Matches accents, emojis, CJK
`^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$`	UUID v4	550e8400-e29b-41d4-a716-446655440000
`^\s+\|\s+$`	Leading/trailing whitespace	Use with .replace() to trim

Yes. Regex Cheatsheet is completely free on PureBrowser — every feature, with no account, no trial, and no credit card.

No. Regex Cheatsheet runs entirely inside your browser, so anything you type, paste, or open stays on your own device.

Neither. There is no account and nothing to download — open the page and Regex Cheatsheet is ready to use on desktop or mobile.

Once the page has loaded, yes. All of the processing happens locally in your browser, so it keeps working without a connection.

Folder Structure Generator

Build folder structure diagrams, ASCII directory trees, and file tree visualizations for READMEs and docs.

.gitignore Generator

Generate merged .gitignore rules for your stack with one click.

JSON to TypeScript Interface

Convert JSON into TypeScript interfaces with inferred nested types.

Text to Slug Converter

Convert titles and phrases into clean SEO-friendly URL slugs.

UTM Builder

Build campaign URLs with UTM parameters for analytics tracking.

JSON Formatter & Validator

Validate, format, and minify JSON directly in your browser.