Regular Expressions 101

Save & Share

  • Regex Version: ver. 3
  • 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

Substitution

Processing...

Code Generator

Language

Generated Code

# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression. sed -E 's/(?:^|\ |\n)(((?:(?:http(?:s)?\:)?(?:\\/\\/))|(?:\\/\\/))?(?:(?=[a-z0-9\-\.]{1,255}(?=\\/|\ |$|\:|\n|\?|\,|\!))(?:(?:(?:[a-z0-9]{1}(?:[a-z0-9\-]{1,62})?\.){1,127})[a-z]{2,}(?:\.[a-z]{2})?))(?:[a-z0-9\\/\-\_\%\?\&\!\$\'\,\(\)\*\.\+\=\;])*?)(?=$|\.(?=\ |$)|\:|\n|\ |\?(?=\ |$)|\,|\!)/<a href="$1">$1<\/a>/ig;t' <<< "I really like to go to google.com and google stuff. <br> I also like http://hercdev.io, both are pretty cool! http://google.com <br> This is the url to an image: https://objects.dreamhost.com/herc-scripts/chicken_sombrero.gif <br> But this is the actual image: <img src=\"https://objects.dreamhost.com/herc-scripts/chicken_sombrero.gif\" style=\"max-width: 100px;\" /> <br> Note that the url to the image in the &lt;img&gt; tag is unaffected. This is true for things that are already links also, like <a href=\"http://google.com\" target=\"_blank\">this.</a>"

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 SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html