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Regex Cheatsheet
Regular expression syntax reference
Regular expression syntax cheatsheet. Quick reference for regex patterns, quantifiers, character classes, and anchors. Free regex guide.
Character Classes
.Any character except newline\dDigit (0-9)\DNot a digit\wWord character (a-z, A-Z, 0-9, _)\WNot a word character\sWhitespace (space, tab, newline)\SNot whitespace[abc]Any of a, b, or c[^abc]Not a, b, or c[a-z]Character range a-z[A-Za-z]Any letter[0-9]Any digitAnchors
^Start of string (or line with m flag)$End of string (or line with m flag)\bWord boundary\BNot a word boundary(?=...)Positive lookahead(?!...)Negative lookahead(?<=...)Positive lookbehind(?<!...)Negative lookbehindQuantifiers
*Zero or more+One or more?Zero or one (optional){n}Exactly n times{n,}n or more times{n,m}Between n and m times*?Zero or more (lazy)+?One or more (lazy)??Zero or one (lazy)Groups & References
(...)Capturing group(?:...)Non-capturing group(?<name>...)Named capturing group\1Backreference to group 1\k<name>Backreference to named group(a|b)Match a or bEscape Sequences
\nNewline\rCarriage return\tTab\0Null character\.Escaped special character (literal dot)\\BackslashFlags
gGlobal - find all matchesiCase insensitivemMultiline - ^ and $ match line boundariessDotall - . matches newlinesuUnicode supportySticky - match at lastIndex positionCommon Patterns
^[\w.-]+@[\w.-]+\.[a-zA-Z]{2,}$Email address^https?://[\w.-]+(?:/[\w./-]*)?$URL^\d{3}-\d{3}-\d{4}$Phone number (US)^\d{5}(-\d{4})?$ZIP code (US)^#?([a-fA-F0-9]{6}|[a-fA-F0-9]{3})$Hex color^\d{4}-\d{2}-\d{2}$Date (YYYY-MM-DD)^(?:\d{1,3}\.){3}\d{1,3}$IPv4 address (simple)^[a-z0-9-]+$Slug (lowercase, numbers, dashes)
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