21+ FREE Regular Expression Tools & Resources (for .Net Developers)

By | October 20, 2007

Love ’em or hate ’em, there’s no denying that regular expressions are an important tool for parsing text.

I’ve created a list of 21+ FREE tools and resources that may make writing regular expressions a bit easier.

Most likely I’ve missed a few, so if you know of any that should be included, leave a comment and let me know.

kick it on DotNetKicks.com

Desktop Tools

Rad Software Regular Expression Designer v1.4

Screen shots: Default Layout, Modified Layout

Unlike Regular Expressions, Rad Software’s Regular Expression Designer is clean looking and easy to use.

The main screen of the designer is broken up into 6 sections, Input Text, Regular Expression, Replace Expression, Replace Results, Options, Match Results, and Language Elements (Reference).

Each of these sections can be resized, moved around to various spots on the screen, combined with another section with each section having its own tab, or the sections can float on top of the application. I did have some issues trying to move the sections back to their defaults.

The two things that impressed me in Regular Expression Designer are the Match Results section, which breaks down any matches that were found into a tree/folder view, and the Language Elements which will help make writing your regular expressions much easier

There were a few things though that I didn’t like about it, such as the Undo command only remembers the last action, there’s no VB/C# Source Code generator like in some of the other applications, and the reorganizing of the layout is a bit flaky. I was unable to move the sections back to their original position, and there’s nothing under the View menu to do so.


RegexDesigner.NET v1.0.2727 (beta)

Screen shots: Default Layout – Regular Expression, Default Layout – String Replacement, Options Menu, Generate Code

Don’t be fooled by the simple layout, RegexDesigner.NET packs a bit of a punch. Some of its features include:

  • Full source code
  • Interactive matching of .NET regular expressions.
  • Syntax highlighted match results, including zero-length matches and hidden characters.
  • Tooltips to display matched groups.
  • Regular expression matching, replacing and splitting.
  • Regular expression projects to save expressions, text to match and all regex options.
  • Full code generation for C# and VB.NET for all regex operations.
  • Compiled assembly generation.
  • Full online help.

When you download RegexDesigner.NET, you’ll download the full source code. Hidden in the \redist folder is where you will find RegexDesigner.exe. If you’re running Vista, you’ll need to run it as Administrator, or else it won’t run.

One feature that I would really like to see (in all RegEx designers) is some sort of library or reference, other than that, this is a great application.


The Regulator v2.0

Screen shots: Default Layout, Generate Code, Regex Analyzer, Web Search

This is the first of three regular expression tools in this list from Roy Osherove (you’ll have to scroll down to find the other two). On almost every "Must Have Tools" list that I’ve read, this tool is mentioned, so it must be good, right?

Maybe it’s just me, which wouldn’t be a surprise, but I don’t see what all of the fuss is about. I downloaded the source about a week ago, gave it a whirl, and found that the UI wasn’t too friendly compared to a lot of the other tools in the list, and the one feature that makes it stand out, the Web Search, didn’t work.

So last night I visited the site and seen that the Regulator Binaries (.NET 2.0 3.X) were just released that day. So I downloaded it, pretty sure that the problems I had with the previous download which was released over a year ago would be fixed, and I’d have something good to say. But, as my luck would have it, nothing has changed.

As soon as a new release is out, and it works (on my computer), I’ll write a whole post just for its review. Hopefully I’ll have a bit more luck with the other two tools from Roy Osherove.


Expresso v3.0

Screen shots: Test Mode, Design Mode, Library, Tools Menu, View Code, Validation Results

Now here’s a feature full tool, that works.

The main features include a Regex Analyzer that breaks down your expression, Search Results which displays the matches in a treeview, Validation Results that goes through each line in your Sample Text and displays whether or not that line validates, a Library that comes with 33 examples (you can add more expressions to it), Recent Expressions which is a history of your expressions, and View Code, which will generate code in C#, Visual Basic, Managed C++ and C++/CLI.

Overall, I think this is a great tool. However, there is one are that it can be improved on, and that’s the layout. There are tons of features and options available in Expresso, which are spread out over three tabs. I think (but could be wrong), that one screen is all that is needed. The Expression Library could be included on the right or left side of the main screen, which would eliminate one tab. The Replacement section takes up so little space, and could also be place in the main screen. As for the Options section (under the Design Mode tab), I haven’t yet figured out where this could go.


Regulazy v1.0.3.0 (Beta)

Screen shots: Screen shot #1, Screen shot #2, Screen shot #3, Code Sample, Short Date, Matches

Regulazy is the second of three Regular Expression tools from Roy Osherove. Roy describes it as a visual Regex Creation tool for beginners.

Unlike most regular expression tools, Regulazy uses point and click to try and create patterns based on the text that you entered.

But like The Regulator, I had several issues with this tool. First off "New", "Open", and "Save" options do nothing. Secondly, Regulazy crashes if you press "Auto Match" twice, whether it be two consecutive clicks, or two clicks with some other actions between. Thirdly, the regular expressions are too general. For example, when I highlighted a date, it gave me the option to use ShortDate(xx/xx/xxxx). So it did recognize that the string that I selected was a Date, however, the pattern that it produced was "\d{2}/\d{2}/\d{4}", which says that along as the date has two digits, a /, another two digits, another / and then four more digits, then its a match. So 04/08/200 would be valid, but so would 99/99/2007. Yes, the regular expression can be modified to meet your needs (but it will change it back to its own expression), but the tool is for beginners.


Visual REGEXP v3.1

Screen shots: Screen shot #1, Screen shot #2, Screen shot #3

Visual REGEXP is another clean looking, simple to use regular expression tool. Just enter in your pattern, add some text, and click match. If the text you entered matches the pattern, then it will be highlighted in different colours. It also includes a couple of popular patterns that you can use, including Date in the format of mm/dd/yyyy or dd/mm/yyyy, instead of xx/xx/xxxx.

I think with a few small improvements, this could be a pretty decent tool. A seperate panel for matches would be a big improvement. Currently your matches are displayed where your string input was. So every time you match your string to the expression, you have to retype your string. The Help section could use a major makeover, and the included expressions are lacking (9 are included).


RegExBuilder v1.3.0

Screen shots: Default Screen, Match Found, Error in Pattern, Opacity

RegExBuilder is probably the simplest (in terms of features)of all of the tools. It doesn’t come with any included patterns or references, has hardly any options to choose from, doesn’t have any kind of visualizer to break down your matches, and won’t generate source code for you.

All that it has is three text boxes, one for your pattern, and two for text. After creating your expression, and filling out one or both of the text textboxes, it will inform you if there is a match by changing the background color of the two textboxes to either green or red (I’m sure you can figure out what the colours represent). And if there is a problem with your pattern, then its textbox will be orange.

The only options that are included are "IgnoreCase", "IgnorePatternWhitespace", "Always on top" and "Windows Opacity".

This is definitely not a tool for any RegEx n00bs, and with all of the other tools out there to choose from, I can’t see too many experienced RegExers using this.


Regular Expression Visualizers

Screen shots: Screen shot #1, Screen shot #2

I was really tempted to come up with some cheesey "It’s the bottom of the ninth inning, two out, and Roy is at bat with two strikes …." line to start this off, but decided not to.

Roy’s Regular Expression Visualizer (which has also been mentioned in my previous "15+ Free Visual Studio Add-Ins" post) is unlike any of the other tools that have been mentioned so far. You can’t just click on it to make it run. You can’t give it a string to run your expression against, heck, you don’t even give it a regular expresion. Not directly anyways.

Regular Expression Visualizer is an addin for Visual Studio, which allows you to ‘Visualize’ regular expressions that are in your code. It will allow you to visualize the following types: System.String, System.Text.RegularExpressions.Regex, System.Text.RegularExpressions.Match and System.Text.RegularExpressions.MatchCollection


Web Tools

RETester: Probably the ugliest of all of the Web Tools (take the ad out), and suprisingly it doesn’t come with any references or examples. I say suprisingly because its part of regexlib.com, which is one, if not the biggest resource for regular expressions (see down below).

JavaScript Regular Expression Validator: This and RegEx Builder (above) are pretty similar. Not sure which came first, so I won’t say that this looks like that, or vice versa. This tool, like RegEx Builder allows you to specify a Regular Expression pattern, and provide two test strings. If one and/or the other match the patter, ten the textbox goes green, else it’ll stay maroonish. The tester also comes with a small library with examples.

RegEx Pal: A simple JavaScript regular expression tester. It uses color highlighting to show matches.

Rex V: This tool is actually three Regex Evaluators in one. The three evaluators are for PCRE (Perl Compatible Regular Expressions), POSIX and JavaScript.

A Better .NET Regular Expression Tester : A regex tool for testing out .Net regular expressions. The results panel breaks down all of the matches, which is a nice feature.

Regular Expression Tool: A really simple AJAXish tool.



RegExLib.com: Has a plethora of information on all things regular expression. At the time of this writing, they have indexed 1802 expressions.

Regular-Expressions.info: Tons of tutorials, examples and resources.

Regular Expressions Cheat Sheet: The Regular Expressions cheat sheet is designed to be printed on an A4 sheet of paper and live by a designer or developer’s desk, to make life a bit easier. The cheat sheet can be downloaded either as a .PNG or a .PDF.

.NET Framework Regular Expressions: MSDN’s Regular Expression section for .Net 2.0.

The 30 Minute Regex Tutorial: Jim Hollenhorst’s goal is to get you up and running with a basic understanding of regular expressions within 30 minutes.

.Net Coders: Regular Expressions: A series of articles that will introduce you to regular expressions, the classes within the System.Text.RegularExpressions namespace, and how to process matches and groups. Examples and sample code are provided.

RegExLib.com Regular Expression Cheat Sheet (.NET): A cheat sheet with lots of information for using Regular Expressions in .Net.


13 thoughts on “21+ FREE Regular Expression Tools & Resources (for .Net Developers)

  1. Pingback: DotNetKicks.com

  2. carlj Post author

    kadir, I’ve ran across it, but its not free, so I didn’t add it to the list.

  3. Pingback: Hosam Kamel

  4. Pingback: Weekly Link Post 12 « Rhonda Tipton’s WebLog

  5. Pingback: Ghillie Suits » 21+ FREE Regular Expression Tools & Resources (for .Net Developers)

  6. carlj Post author

    Hey fish,

    Could you give a brief description for Convert.Net? I quickly looked at the screen shots (I’m at work, so I can’t try it out yet), and it doesn’t look like a Regular Expression tool.


  7. fish

    Hi carlj
    This is a multipurpose conversion utility
    Includes C# VB.NET, Text Translation, En/Decode
    and RegEx Tester…etc.

    Drop down the menu you can change the function

  8. alec

    Hi thanks,
    Your list of software and reviews was very helpful, and saved me a bit of time. I like the style of your blog too.
    I’ll be reading some more


  9. Pingback: Recursos para desarrolladores .NET | Diseño Web, programación web, Seo, Marketing, Web 2.0

  10. carlj Post author

    Thanks Julio …. can you resubmit the other link? I was quick on the trigger, and marked it as SPAM.

    Carl J

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.