Regex Cheat Sheet
A searchable reference of character classes, anchors, quantifiers, groups, flags, and common ready-to-use patterns.
Character classes
.Any character except newline\dAny digit (0-9)\DAny non-digit\wWord character (letters, digits, underscore)\WNon-word character\sWhitespace character\SNon-whitespace character[abc]Any of a, b, or c[^abc]Any character except a, b, or c[a-z]Any lowercase letterAnchors
^Start of string (or line, with m flag)$End of string (or line, with m flag)\bWord boundary\BNot a word boundaryQuantifiers
*0 or more+1 or more?0 or 1 (optional){n}Exactly n times{n,}n or more times{n,m}Between n and m times*?0 or more, lazy (shortest match)Groups & alternation
(abc)Capture group(?:abc)Non-capturing group(?<name>abc)Named capture groupa|bMatch a or b(?=abc)Positive lookahead(?!abc)Negative lookahead(?<=abc)Positive lookbehind(?<!abc)Negative lookbehindFlags
gGlobal — find all matches, not just the firstiCase-insensitivemMultiline — ^ and $ match line boundariessDot matches newline toouUnicode modeCommon patterns
^[\w.-]+@[\w.-]+\.\w+$Basic email address^https?:\/\/.+URL starting with http(s)^\d{3}-\d{3}-\d{4}$US phone number (123-456-7890)^#([0-9a-fA-F]{3}){1,2}$Hex color code^\d{4}-\d{2}-\d{2}$ISO date (YYYY-MM-DD)Example input
lookahead
Example output
(?=abc) — Positive lookahead