Regex Cheatsheet

A clean searchable reference of regex syntax with copyable examples.

Anchors

^Start of string (or line in m mode)

$End of string (or line in m mode)

\bWord boundary

\BNon-word boundary

Character classes

.Any character except newline

\dDigit (0-9)

\DNon-digit

\wWord character (a-z, A-Z, 0-9, _)

\WNon-word character

\sWhitespace

\SNon-whitespace

[abc]Any of a, b, or c

[^abc]Not a, b, or c

[a-z]Range a through z

Quantifiers

*0 or more (greedy)

+1 or more (greedy)

?0 or 1

{n}Exactly n

{n,}n or more

{n,m}Between n and m

*?0+ (lazy)

+?1+ (lazy)

Groups & references

(...)Capturing group

(?:...)Non-capturing group

(?<name>...)Named capturing group

\1, \2Backreference to group

\k<name>Backreference to named group

Lookarounds

(?=...)Positive lookahead

(?!...)Negative lookahead

(?<=...)Positive lookbehind

(?<!...)Negative lookbehind

Flags

gGlobal - find all matches

iCase-insensitive

mMultiline - ^ and $ match line boundaries

sDotall - . matches newline

uUnicode mode

ySticky - match at lastIndex only

Common patterns

^[\w.+-]+@[\w-]+\.[\w.-]+$Email (pragmatic)

^https?://\S+$URL (http or https)

^\d{3}-?\d{3}-?\d{4}$US phone

^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$ISO date YYYY-MM-DD

^[a-z0-9]+(?:-[a-z0-9]+)*$URL slug

^#?([\dA-Fa-f]{3}|[\dA-Fa-f]{6})$Hex color