Regex Cheat Sheet
A comprehensive guide to regular expressions with patterns, examples, and explanations
Anchors
^Start of input or line (with multiline flag)
\AStart of string only
$End of input or line (with multiline flag)
\ZEnd of string only
\bWord boundary (between word and non-word)
\BNon-word boundary
\<Start of word
\>End of word
Character Classes
\cControl character (e.g., \cM for Control-M)
\sWhitespace (space, tab, line feed)
\SNon-whitespace character
\dDigit (0-9)
\DNon-digit character
\wWord character (A-Z, a-z, 0-9, _)
\WNon-word character
\xHex character (e.g., \x41 for "A")
\OOctal character (e.g., \101 for "A")
\p{L}Any letter (Unicode)
\p{N}Any number (Unicode)
\p{P}Any punctuation (Unicode)
\p{S}Any symbol (Unicode)
Quantifiers
*0 or more (greedy)
+1 or more (greedy)
?0 or 1 (greedy)
{3}Exactly 3 times
{3,}3 or more times
{3,5}3 to 5 times
*?0 or more (lazy)
+?1 or more (lazy)
??0 or 1 (lazy)
Groups and Ranges
.Any character except line terminators
(a|b)Either "a" or "b"
(...)Capturing group
(?:...)Non-capturing group
(?<name>...)Named capturing group
\k<name>Reference to named group
[abc]Any of a, b, or c
[^abc]Not a, b, or c
[a-q]Any lowercase letter a to q
[A-Q]Any uppercase letter A to Q
[0-7]Any digit 0 to 7
Assertions
x(?=y)x followed by y (lookahead)
x(?!y)x not followed by y (negative lookahead)
(?<=y)xx preceded by y (lookbehind)
(?<!y)xx not preceded by y (negative lookbehind)
Special Characters
\nLine feed (U+000A)
\rCarriage return (U+000D)
\tTab (U+0009)
\vVertical tab (U+000B)
\fForm feed (U+000C)
\xxxOctal character (e.g., \101 for "A")
\xhhHex character (e.g., \x41 for "A")
\u{hhhh}Unicode character (e.g., \u{1F600} for "😀")
Flags
gGlobal search (all matches)
iCase-insensitive
mMultiline (^ and $ match line starts/ends)
sDot matches newlines
uUnicode support
ySticky search (from lastIndex)
dGenerate match indices