regex tester

regular expression pattern cheat sheet

character matching

.

any character

\w

any word character (alphanumeric, underscore)

\W

any character that is not a word character (alphanumeric, underscore)

\d

any digit character (0-9)

\D

any character that is not a digit character (0-9)

\s

any whitespace character (space, tab, line break)

\S

any character that is not a whitespace character (space, tab, line break)

character sets

[ABC]

any single character in the set

[^ABC]

any single character that is not in the set

[a-z] or [0-9]

any single character in the given range

special characters

\t

tab

\r

carriage return

\n

line break

escaped characters

\\

\

\.

.

\+

+

\*

*

\?

?

\^

^

\$

$

\[

[

\]

]

\(

(

})

(

\{

{

\}

}

\|

|

\/

/

\'

'

\#

#

$$

$

quantifiers

?

optional - 0 or 1 of the preceding token

*

0 or more of the preceding token

*?

0 or more of the preceding token, but as few as possible before processing the next token

+

1 or more of the preceding token

+?

1 or more of the preceding token, but as few as possible before processing the next token

{2}

exactly 2 of the preceding token

{3,8}

3 to 8 of the preceding token

{3,8}?

3 to 8 of the preceding token, but as few as possible before processing the next token

anchors

^

the beginning of a string

$

the end of a string

\b

word boundary position (whitespace, beginning or end of a string)

\B

any position that is not a word boundary position

groups

(ABC)

groups multiple tokens and create a capture group

(?:ABC)

groups multiple tokens without creating a capture group

look around

(?=ABC)

positive look ahead - match a group after the main expression without including it in the result

(?!ABC)

negative look ahead - a group after the main expression which must not match

(?<=ABC)

positive look behind - match a group before the main expression without including it in the result

(?<!ABC)

negative look behind - a group before the main expression which must not match

alternative

|

or - match expression before or after

replacing

$1

insert result of first capture group

$3

insert result of third capture group

$&

insert matched substring

$`

insert portion of string that precedes the match

$'

insert portion of string that follows the match