.* Regex Cheat Sheet
Regular expression syntax cheat sheet, containing common patterns, character sets, quantifiers, and other references
⚡ Quick Test
Test results will appear here
📝 Common Characters
Pattern Instructions Example
. Any character (except newline) a.c matches abc, aac
\d Digit [0-9] \d{3} matches 123
\D non-digit \D+ matches abc
\w Alphanumeric underscore [a-zA-Z0-9_] \w+ matches word_123
\W non-word character \W+ matches !@#
\s Whitespace characters (space, tab, etc.) \s+ matches whitespace
\S non-whitespace character \S+ matches abc
🔐 Escape Characters
Pattern Instructions Example
\. Matches the dot itself \.com matches .com
\\ Matches backslash \\ matches \
\* Matches asterisk \* matches *
\+ Matches plus sign \+ matches +
\? Matches question mark \? matches ?
\( Matches left parenthesis \( matches (
\) Matches right parenthesis \) matches )
\[ Matches left bracket \[ matches [
\] Matches right bracket \] matches ]
\{ Matches left brace \{ matches {
\} Matches right brace \} matches }
\| Matches vertical bar \| matches |
\- Matches hyphen \- matches -
\^ Matches caret \^ matches ^
\$ Matches dollar sign \$ matches $
🔢 Quantifiers
Pattern Instructions Example
* 0 or more times ab* matches a, ab, abb
+ 1 or more times ab+ matches ab, abb
? 0 or 1 time ab? matches a, ab
{n} Exactly n times a{3} matches aaa
{n,} At least n times a{2,} matches aa, aaa
{n,m} Between n and m times a{2,4} matches aa, aaa, aaaa
*? Non-greedy 0 or more times <.+?> matches shortest HTML tag
+? Non-greedy 1 or more times <.+?> matches shortest HTML tag
📍 Boundary Anchors
Pattern Instructions Example
^ string start ^abc matches abc...
$ string end abc$ matches ...abc
\b word boundary \bword\b matches word
\B Non-word boundary \Bword\B matches sword
\A String start (multiline) \Aabc matches abc
\Z String end (multiline) abc\Z matches abc
🎨 Character Sets
Pattern Instructions Example
[abc] Matches a, b, or c [abc] matches a, b, c
[^abc] Does not match a, b, or c [^abc] matches d, e, f
[a-z] Lowercase letters [a-z] matches a to z
[A-Z] Uppercase letters [A-Z] matches A to Z
[0-9] Digits [0-9] matches 0 to 9
[a-zA-Z] All letters [a-zA-Z] matches a-z, A-Z
[\u4e00-\u9fa5] Chinese characters [\u4e00-\u9fa5]+ matches Chinese characters
📦 Grouping and Capturing
Pattern Instructions Example
(abc) capturing group (\d{3}) matches and captures digits
(?:abc) Non-capturing group (?:\d{3}) matches but does not capture
(? abc) Named capturing group (? \d+) named capture
\1 Reference group 1 (\w)\1 matches aa, bb
\2 Reference group 2 (\w)(\w)\2 matches aba
(?=abc) positive lookahead \w+(?=\.com) matches domain name
(?!abc) negative lookahead \w+(?!\.com) does not match .com
(?<=abc) positive lookbehind (?<=\$)\d+ matches amount
(? negative lookbehind (?
🎯 Common Regex Patterns
purpose regular expression Instructions
email ^\w+@\w+\.\w+$ Basic email format
phone number ^1[3-9]\d{9}$ China mainland phone number
ID number ^\d{17}[\dXx]$ 18-digit ID number
URL https?:\/\/[\w\-\.]+(:\d+)?(\/.*)? HTTP/HTTPS link
IP address ^(\d{1,3}\.){3}\d{1,3}$ IPv4 address
date ^\d{4}-\d{2}-\d{2}$ YYYY-MM-DD format
time ^\d{2}:\d{2}:\d{2}$ HH:MM:SS format
Chinese characters [\u4e00-\u9fa5] Single Chinese character
HTML tag <[^>]+> Matches HTML tag
hex color ^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$ #FFF or #FFFFFF
username ^[a-zA-Z0-9_]{3,16}$ 3-16 characters
strong password ^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{8,}$ Uppercase + lowercase + number + 8 chars
🚩 Flags
flag Instructions Example
g Global match, find all matches /a/g matches all a
i Ignore case /abc/i matches ABC, abc
m Multiline pattern, ^$ matches line start/end /^abc/m matches line start
s Single-line pattern, . matches newline /a.b/s matches a\nb
u Unicode pattern /\u{1F600}/u matches emoji
y Sticky match, starts from lastIndex /a/y strictly starts from index
💡 Instructions
Quick copy: Click the button below the table to quickly copy common regular expressions

Real-time test: Enter text and regular expression in the top test area, click "Test Match" to see results

JavaScript example:
const regex = /\d+/g;
const matches = "abc123".match(regex); // ["123"]

Common methods:
• test() - Test if matches
• exec() - Execute matches and return result
• match() - Find matches
• replace() - Replace matches
• split() - Split string by pattern
💡 About Regex Cheat Sheet: Our comprehensive regex cheat sheet is a complete reference guide for regular expressions. Includes common patterns, character sets, quantifiers, anchors, grouping, and flags. Test your regular expressions in real-time with the built-in tester. Perfect for developers, data analysts, and anyone working with pattern matching and text validation.
📝 Regex Cheat Sheet Features:
• Complete regular expression syntax reference
• Common character sets and patterns
• Quantifiers and repetition operators
• Anchors and boundaries
• Grouping and capturing
• Lookahead and lookbehind assertions
• Common regex patterns (email, phone, URL, etc.)
• Flags and modifiers reference
• Real-time regex testing tool

🔍 Regex Use Cases:
• Form validation (email, phone, password)
• Data extraction from text
• String parsing and manipulation
• Search and replace operations
• Log file analysis
• Web scraping and data cleaning
• Code refactoring and automation