JavaScript Regular Expression cheatsheet with all common regex syntax and examples
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
. or [^\n\r] | any character excluding a newline or carriage return |
[A-Za-z] | alphabet |
[a-z] | lowercase alphabet |
[A-Z] | uppercase alphabet |
\d or [0-9] | digit |
\D or [^0-9] | non-digit |
_ | underscore |
\w or [A-Za-z0-9_] | alphabet, digit or underscore |
\W or [^A-Za-z0-9_] | inverse of \w |
\S | inverse of \s |
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
| space |
\t | tab |
\n | newline |
\r | carriage return |
\s | space, tab, newline or carriage return |
Think of a character set as an OR operation on the single characters that are enclosed between the square brackets. Use ^ after the opening [ to "negate" the character set. Within a character set, . means a literal period.
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
[xyz] | either x, y or z |
[^xyz] | neither x, y nor z |
[1-3] | either 1, 2 or 3 |
[^1-3] | neither 1, 2 nor 3 |
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
\. | period |
\^ | caret |
\$ | dollar sign |
\| | pipe |
\\ | back slash |
\/ | forward slash |
\( | opening bracket |
\) | closing bracket |
\[ | opening square bracket |
\] | closing square bracket |
\{ | opening curly bracket |
\} | closing curly bracket |
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
\\ | back slash |
\] | closing square bracket |
The quantifier goes after the expression to be quantified.
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
{2} | exactly 2 |
{2,} | at least 2 |
{2,7} | at least 2 but no more than 7 |
* | 0 or more |
+ | 1 or more |
? | exactly 0 or 1 |
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
^ | start of string |
$ | end of string |
\b | word boundary |
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
foo|bar | match either foo or bar |
foo(?=bar) | match foo if it's before bar |
foo(?!bar) | match foo if it's not before bar |
(?<=bar)foo | match foo if it's after bar |
(?<!bar)foo | match foo if it's not after bar |
Capturing groups are only relevant in the following methods: string.match(regexp), string.matchAll(regexp), string.replace(regexp, callback). \N is a backreference to the Nth capturing group. Capturing groups are numbered starting from 1.
| Expression | JavaScript Regular Expression cheatsheet with all common regex syntax and examples |
|---|---|
(foo) | capturing group; match and capture foo |
(?:foo) | non-capturing group; match foo but without capturing foo |
(foo)bar\1 | \1 is a backreference to the 1st capturing group; match foobarfoo |
^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ Validates standard email address format, supports multiple domains and subdomains
^(\+?1[-.\s]?)?\(?([0-9]{3})\)?[-.\s]?([0-9]{3})[-.\s]?([0-9]{4})$ Matches US phone number format with various separators and optional country code
^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$ Requires at least 8 characters with uppercase, lowercase, digits and special characters
https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*) Matches HTTP/HTTPS URLs with subdomains, paths and query parameters
^(0[1-9]|1[0-2])\/(0[1-9]|[12][0-9]|3[01])\/\d{4}$ Matches MM/DD/YYYY date format with month and day validation
^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|3[0-9]{13}|6(?:011|5[0-9]{2})[0-9]{12})$ Validates major credit card brand formats (Visa, MasterCard, Amex, etc.)