Regular Expression Cheat Sheet
Detailed regular expression patterns guide
Regular Expression Cheat Sheet
Comprehensive reference guide for Regular Expressions with common patterns. Click the copy button to copy any pattern.
99
Total Commands
99
Filtered Results
Character Classes
| Command | Copy | Description |
|---|---|---|
. | Any character except newline | |
\d | Any digit [0-9] | |
\D | Any non-digit | |
\w | Word character [a-zA-Z0-9_] | |
\W | Non-word character | |
\s | Whitespace character | |
\S | Non-whitespace character | |
[abc] | Any of a, b, or c | |
[^abc] | Not a, b, or c | |
[a-z] | Character between a and z | |
[A-Z] | Character between A and Z | |
[0-9] | Any digit | |
[a-zA-Z] | Any letter |
Quantifiers
| Command | Copy | Description |
|---|---|---|
* | Zero or more | |
+ | One or more | |
? | Zero or one | |
{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) | |
{n,}? | n or more (lazy) | |
{n,m}? | n to m (lazy) |
Anchors
| Command | Copy | Description |
|---|---|---|
^ | Start of string/line | |
$ | End of string/line | |
\b | Word boundary | |
\B | Not word boundary | |
\A | Start of string | |
\Z | End of string | |
\z | Absolute end of string |
Groups and Capturing
| Command | Copy | Description |
|---|---|---|
(abc) | Capturing group | |
(?:abc) | Non-capturing group | |
(?<name>abc) | Named capturing group | |
\1 | Backreference to group 1 | |
\k<name> | Named backreference | |
(?=abc) | Positive lookahead | |
(?!abc) | Negative lookahead | |
(?<=abc) | Positive lookbehind | |
(?<!abc) | Negative lookbehind |
Alternation
| Command | Copy | Description |
|---|---|---|
a|b | a or b | |
(cat|dog) | cat or dog |
Special Characters
| Command | Copy | Description |
|---|---|---|
\ | Escape special character | |
\n | Newline | |
\r | Carriage return | |
\t | Tab | |
\v | Vertical tab | |
\f | Form feed | |
\0 | Null character | |
\xhh | Hex character | |
\uhhhh | Unicode character |
Flags/Modifiers
| Command | Copy | Description |
|---|---|---|
i | Case-insensitive | |
g | Global match | |
m | Multiline | |
s | Dot matches newline | |
u | Unicode | |
x | Extended (ignore whitespace) | |
y | Sticky |
Email Validation
| Command | Copy | Description |
|---|---|---|
^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ | Basic email validation | |
^[\w.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$ | Email with subdomains |
URL Validation
| Command | Copy | Description |
|---|---|---|
^https?://[^\s]+$ | Basic URL | |
^(https?|ftp)://[^\s/$.?#].[^\s]*$ | URL with protocols | |
^https?://([\w-]+\.)+[\w-]+(/[\w-./?%&=]*)?$ | Complete URL validation |
Phone Numbers
| Command | Copy | Description |
|---|---|---|
^\d{3}-\d{3}-\d{4}$ | US phone (xxx-xxx-xxxx) | |
^\(?\d{3}\)?[- ]?\d{3}[- ]?\d{4}$ | Flexible US phone | |
^\+?\d{1,3}?[- ]?\(?\d{1,4}\)?[- ]?\d{1,4}[- ]?\d{1,9}$ | International phone |
Dates
| Command | Copy | Description |
|---|---|---|
^\d{4}-\d{2}-\d{2}$ | Date (YYYY-MM-DD) | |
^\d{2}/\d{2}/\d{4}$ | Date (MM/DD/YYYY) | |
^(0[1-9]|1[0-2])/(0[1-9]|[12]\d|3[01])/\d{4}$ | Validated MM/DD/YYYY |
Time
| Command | Copy | Description |
|---|---|---|
^([01]?[0-9]|2[0-3]):[0-5][0-9]$ | Time (HH:MM 24-hour) | |
^(0?[1-9]|1[0-2]):[0-5][0-9] (AM|PM)$ | Time (12-hour with AM/PM) |
IP Addresses
| Command | Copy | Description |
|---|---|---|
^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$ | IPv4 address | |
^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ | Valid IPv4 |
Credit Cards
| Command | Copy | Description |
|---|---|---|
^4[0-9]{12}(?:[0-9]{3})?$ | Visa card | |
^5[1-5][0-9]{14}$ | MasterCard | |
^3[47][0-9]{13}$ | American Express | |
^3(?:0[0-5]|[68][0-9])[0-9]{11}$ | Diners Club |
Passwords
| Command | Copy | Description |
|---|---|---|
^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{8,}$ | Strong password (8+ chars, upper, lower, digit) | |
^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&]).{8,}$ | Strong password with special char |
Usernames
| Command | Copy | Description |
|---|---|---|
^[a-zA-Z0-9_]{3,16}$ | Username (3-16 alphanumeric) | |
^[a-zA-Z][a-zA-Z0-9_]{2,15}$ | Username (starts with letter) |
Colors
| Command | Copy | Description |
|---|---|---|
^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$ | Hex color code | |
^rgb\(\s*\d{1,3}\s*,\s*\d{1,3}\s*,\s*\d{1,3}\s*\)$ | RGB color |
Numbers
| Command | Copy | Description |
|---|---|---|
^-?\d+$ | Integer | |
^-?\d*\.?\d+$ | Decimal number | |
^-?\d+(\.\d{1,2})?$ | Decimal with 1-2 places | |
^\d{1,3}(,\d{3})*$ | Number with commas |
HTML/XML
| Command | Copy | Description |
|---|---|---|
<([a-z]+)([^>]*)>(.*?)</\1> | HTML tag with content | |
<([a-z]+)([^>]*)/> | Self-closing tag | |
<!--.*?--> | HTML comment |
Files
| Command | Copy | Description |
|---|---|---|
\.txt$ | Text file | |
\.(jpg|jpeg|png|gif)$ | Image file | |
\.(pdf|doc|docx|txt)$ | Document file |
Social Media
| Command | Copy | Description |
|---|---|---|
^@[a-zA-Z0-9_]{1,15}$ | Twitter handle | |
^#[a-zA-Z0-9_]+$ | Hashtag |
Common Patterns
| Command | Copy | Description |
|---|---|---|
^[a-zA-Z\s]+$ | Letters and spaces only | |
^[a-zA-Z0-9]+$ | Alphanumeric only | |
^\s*$ | Empty or whitespace | |
^(?!\s*$).+ | Not empty |
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