Regular Expressions 101

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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]
  • Character class intersection
    [\w&&[^\d]]
  • 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
Processing...

Test String

Substitution
Processing...

Code Generator

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(href|src)=\""\/"; string substitution = @""; string input = @"""<!DOCTYPE html><html lang=""en"" class=""notion-html""><head><meta charset=""utf-8""><meta name=""viewport"" content=""width=device-width,height=device-height,initial-scale=1,maximum-scale=1,user-scalable=no,viewport-fit=cover""><title>Notion – The all-in-one workspace for your notes, tasks, wikis, and databases.</title><meta name=""description"" content=""A new tool that blends your everyday work apps into one. It's the all-in-one workspace for you and your team""><script type=""text/javascript"">window.__webStartTime=Date.now()</script><meta name=""twitter:card"" content=""summary_large_image""><meta name=""twitter:site"" content=""@NotionHQ""><meta name=""twitter:title"" content=""Notion – The all-in-one workspace for your notes, tasks, wikis, and databases.""><meta name=""twitter:description"" content=""A new tool that blends your everyday work apps into one. It's the all-in-one workspace for you and your team""><meta name=""twitter:url"" content=""https://www.notion.so""><meta name=""twitter:image"" content=""https://www.notion.so/images/meta/default.png""><meta property=""og:site_name"" content=""Notion""><meta property=""og:type"" content=""website""><meta property=""og:url"" content=""https://www.notion.so""><meta property=""og:title"" content=""Notion – The all-in-one workspace for your notes, tasks, wikis, and databases.""><meta property=""og:description"" content=""A new tool that blends your everyday work apps into one. It's the all-in-one workspace for you and your team""><meta property=""og:image"" content=""https://www.notion.so/images/meta/default.png""><meta property=""og:locale"" content=""en_US""><link rel=""shortcut icon"" type=""image/x-icon"" href=""/images/favicon.ico""><link rel=""apple-touch-icon"" href=""/images/logo-ios.png""><meta name=""apple-mobile-web-app-capable"" content=""yes""><meta name=""apple-itunes-app"" content=""app-id=1232780281""><meta name=""format-detection"" content=""telephone=no""><meta name=""msapplication-tap-highlight"" content=""no""><link href=""/print.b31f28aa.css"" rel=""stylesheet"" media=""print""><link href=""/vendors~main-aa07f589b8b4b537cd5a.css"" rel=""stylesheet""><link href=""/app-360d995418be563505cc.css"" rel=""stylesheet""></head><body class=""notion-body""><script type=""text/javascript"">var theme=""light"",localThemeKey=""theme"",themeRecord=localStorage.getItem(""theme"");if(themeRecord){var parsed=JSON.parse(themeRecord);parsed&&parsed.mode&&(theme=parsed.mode)}""dark""===theme&&document.body.classList.add(""dark"")</script><style>body{background:#fff}body.dark{background:#2f3437}.initial-loading-spinner{-webkit-animation:rotate 1s linear infinite;animation:rotate 1s linear infinite;-webkit-transform-origin:center center;transform-origin:center center;width:1em;height:1em;opacity:.5;display:block;pointer-events:none}@-webkit-keyframes rotate{0%{-webkit-transform:rotate(0) translateZ(0);transform:rotate(0) translateZ(0)}100%{-webkit-transform:rotate(360deg) translateZ(0);transform:rotate(360deg) translateZ(0)}}@keyframes rotate{0%{-webkit-transform:rotate(0) translateZ(0);transform:rotate(0) translateZ(0)}100%{-webkit-transform:rotate(360deg) translateZ(0);transform:rotate(360deg) translateZ(0)}}</style><div id=""initial-loading-spinner"" style=""position:absolute;top:0;bottom:0;left:0;right:0;display:flex;align-items:center;justify-content:center;opacity:0""><div class=""initial-loading-spinner"" style=""width:24px;height:24px""><svg xmlns=""http://www.w3.org/2000/svg"" xmlns:xlink=""http://www.w3.org/1999/xlink"" xmlns:sketch=""http://www.bohemiancoding.com/sketch/ns"" width=""100%"" height=""100%"" viewBox=""0 0 24 24"" version=""1.1"" data-ember-extension=""1""><defs><linearGradient x1=""28.1542969%"" y1=""63.7402344%"" x2=""74.6289062%"" y2=""17.7832031%"" id=""linearGradient-1""><stop stop-color=""rgba(164, 164, 164, 1)"" offset=""0%""/><stop stop-color=""rgba(164, 164, 164, 0)"" stop-opacity=""0"" offset=""100%""/></linearGradient></defs><g id=""Page-1"" stroke=""none"" stroke-width=""1"" fill=""none""><g transform=""translate(-236.000000, -286.000000)""><g transform=""translate(238.000000, 286.000000)""><circle id=""Oval-2"" stroke=""url(#linearGradient-1)"" stroke-width=""4"" cx=""10"" cy=""12"" r=""10""/><path d=""M10,2 C4.4771525,2 0,6.4771525 0,12"" id=""Oval-2"" stroke=""rgba(164, 164, 164, 1)"" stroke-width=""4""/><rect id=""Rectangle-1"" fill=""rgba(164, 164, 164, 1)"" x=""8"" y=""0"" width=""4"" height=""4"" rx=""8""/></g></g></g></svg></div></div><script type=""text/javascript"">var isElectron=""undefined""!=typeof global||window.__isElectron,isReactNative=/ReactNative/.test(navigator.userAgent),showSpinner=isElectron||isReactNative;if(showSpinner){var spinner=document.getElementById(""initial-loading-spinner"");spinner&&(spinner.style.opacity=1)}</script><div id=""notion-app""></div><script type=""text/javascript"" src=""/vendors~main-43c644cb58b7f4a0b032.js""></script><script type=""text/javascript"" src=""/app-24e0cf89f2d116fc27a1.js""></script></body></html>"""; RegexOptions options = RegexOptions.Multiline; Regex regex = new Regex(pattern, options); string result = regex.Replace(input, substitution); } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx