Regular Expressions 101

Save & Share

  • Regex Version: ver. 10
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
ig

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?i)[:,\s]\s*url\s*\(\s*(?:'(\S*?)'|"(\S*?)"|((?:\\\s|\\\)|\\\"|\\\'|\S)*?))\s*\)`) var str = `.ac-gn-link-apple{background-repeat:no-repeat;background-size:20px 44px;background-image:url("../images/ac-globalnav/globalnav/apple/image_large.svg");background-position:center center;width:20px}#ac-globalnav.no-svg .ac-gn-link-apple{background-image:url("http://images.apple.com/ac/globalnav/2.0/en_US/images/ac-globalnav/globalnav/apple/image_large.png")}@media only screen and (max-width: 767px){#ac-globalnav .ac-gn-link-apple{background-size:21px 48px;background-image:url("../images/ac-globalnav/globalnav/apple/image_small.svg")}#ac-globalnav.no-svg .ac-gn-link-apple{background-image:url("http://images.apple.com/ac/globalnav/2.0/en_US/images/ac-globalnav/globalnav/apple/image_small.png")}}.ac-gn-current-apple #ac-globalnav .ac-gn-link-apple{opacity:0.65;-ms-filter:'progid:DXImageTransform.Microsoft.Alpha(Opacity=$ieopacity)';filter:alpha(opacity=65)}#ac-globalnav .ac-gn-link-mac{background-repeat:no-repeat;background-size:31px 44px;background-image:url("../images/ac-globalnav/globalnav/links/mac/image_large.svg");background-position:center center;background-origin:content-box;background-size:cover;width:1.72222em;max-width:52.7px}#ac-globalnav.no-svg .ac-gn-link-mac{background-image:url("http://images.apple.com/ac/globalnav/2.0/en_US/images/ac-globalnav/globalnav/links/mac/image_large.png")}@media only screen and (max-width: 767px){#ac-globalnav .ac-gn-link-mac{background-size:37px 48px;background-image:url("../images/ac-globalnav/globalnav/links/mac/image_small.svg")}#ac-globalnav.no-svg .ac-gn-link-mac{background-image:url("http://images.apple.com/ac/globalnav/2.0/en_US/images/ac-globalnav/globalnav/links/mac/image_small.png")}}.ac-gn-current-mac #ac-globalnav .ac-gn-link-mac{opacity:0.65;-ms-filter:'progid:DXImageTransform.Microsoft.Alpha(Opacity=$ieopacity)';filter:alpha(opacity=65)}#ac-globalnav .ac-gn-link-ipad{background-repeat:no-repeat;background-size:30px 44px;background-image:url("../images/ac-globalnav/globalnav/links/ipad/image_large.svg");background-position:center center;background-origin:content-box;background-size:cover;width:1.66667em;max-width:51px}#ac-globalnav.no-svg .ac-gn-link-ipad{background-image:url("http://images.apple.com/ac/globalnav/2.0/en_US/images/ac-globalnav/globalnav/links/ipad/image_large.png")}@media only screen and (max-width: 767px){#ac-globalnav .ac-gn-link-ipad{background-size:35px 48px;background-image:url("../images/ac-globalnav/globalnav/links/ipad/image_small.svg")}#ac-globalnav.no-svg .ac-gn-link-ipad{background-image:url("http://images.apple.com/ac/globalnav/2.0/en_US/images/ac-globalnav/globalnav/links/ipad/image_small.png")}}.ac-gn-current-ipad #ac-globalnav .ac-gn-link-ipad{opacity:0.65;-ms-filter:'progid:DXImageTransform.Microsoft.Alpha(Opacity=$ieopacity)';filter:alpha(opacit... :url(asdawdw) : url(asdawdw) : url (asdawdw) : url ( asdawdw) : url ( asdawdw ) : url ( asdawdw ) :url('asdawdw') : url('asdawdw') : url ('asdawdw') : url ( 'asdawdw') : url ( 'asdawdw' ) : url ( 'asdawdw' ) :url("asdawdw") : url("asdawdw") : url ("asdawdw") : url ( "asdawdw") : url ( "asdawdw" ) : url ( "asdawdw" ) :url(asda\)wdw) :url(asda\))wdw) <- should terminate early, due to unescape paren :url(asda\ wdw) :url(asda\ wdw) <- unescape space, invalid :url(asda\"wdw) :url(asda\" wdw) <- unescape space, invalid :url(asda\'wdw) :url(asda\')wdw) <- should terminate early, due to unescape paren : url ( "asda\"wdw") : url ( 'asda\"wdw') : url ( 'asda\)))wdw') : url ( 'asda\"))wdw') : url ( asda\"))wdw)` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/