Skip to main content

Regex Hero's Debut

So last week I launched and submitted it to a few social bookmarking sites ( happened to be the most effective). Since then I've had 368 visits to the site. That's a pretty strong start for a brand new website.

What Does The Tool Do?
Regex Hero will dynamically highlight regular expression matches as you type. The whole idea behind it is to save as much time as possible and make it as convenient as possible to work with regular expressions.

What's Special About It?
It's the first online .NET regular expression tester with instantaneous highlighting that I know of. (Someone please correct me if I'm wrong.) Microsoft Silverlight lends itself to this functionality perfectly. I essentially wrote it and got it online in 3 days. Since then I've made some tweaks and minor improvements, but nevertheless it was extremely easy to build and I have to thank Microsoft and their development tools for that.

The other thing I was surprised about is just how well .NET regular expressions are optimized. You can see for yourself if you use the benchmark feature in Regex Hero. On my computer it'll perform regular expression matching 500,000 times in one second, easy. The way .NET compiles and caches regular expression seems to really make it scream. That kind of performance helps with the instantaneous highlighting. I mean, you can create a huge target string and it'll still find and highlight the matches within milliseconds after every key press.

Will it Always be Free?
That's a tough question. Most likely, the online version you see now will always be free. But I may at some point create a desktop (WPF) version that I'll sell for cheap.

What's Coming Next?
I'm trying to figure out how to display the exception properly when you write an invalid regular expression. Essentially, since Silverlight excludes the necessary debugging assemblies, it won't provide the same exception detail I'm used to. Once I get that figured out you should see better error messages.

Then the next thing for me to do is add the ability to replace text with regular expressions. Other than that, I'm open to suggestions.


  1. Hey, not that it's a work of art like Regex Hero (kudos) but there is another Silverlight Regular Expression tool - a variant of my tool nregex ( called nregex9 at:

  2. Thanks David.

    That's one I missed. I remember finding your site but I guess I missed your Silverlight version. Google searching > me.


Post a Comment

Popular posts from this blog

Regex Hero for Windows 10 is Underway

Awhile back I began working on an HTML5 / JavaScript version of Regex Hero . However, it was a huge undertaking essentially requiring a complete rewrite of the entire application. I have not had enough time to dedicate to this lately. So I've begun again, this time rewriting Regex Hero to work in WPF. It'll be usable in Windows 10 and downloadable from the Microsoft Store. This is a much easier task that also has the advantage of running the .NET regex library from the application itself. This will allow for the same speedy experience of testing your regular expressions and getting instant feedback that Regex Hero users have always enjoyed. I expect the first release to be ready in Q4 of 2019.

Silverlight 4 Coming in April, or Maybe Sooner

The exact release date has not been announced. But Visual Studio 2010 RTM is coming out in April and I think it's safe to assume that Silverlight 4 will be released no later than that. Each release of Silverlight has brought massive improvements over the previous version. And once again, Silverlight 4 does not disappoint. There is a long list of improvements but the ones that I think that will affect Regex Hero are as follows: RichTextBox My plan is to use this in place of all 4 major textboxes in Regex Hero. The new RichTextBox has built-in multiple undos & redos, so I can ditch my home-brewed code. It should be nice to use for syntax highlighting for the regular expressions I intend to create. It also has a built-in API to determine the pixel position of the text. I should be able to use this API and build a new highlighting scheme based off of it. This should do a couple things. First, I should be able to finally fix the problem I had with the ScrollViewer and

Regex Analysis Bug Fixes

All of these updates relate to the analyzer, so if you're not a Regex Hero Professional user, then this won't affect you. I received a report of an analysis bug  related to character classes.  The regex analyzer wouldn't handle opening brackets inside a character class properly. It's one of the finer details of the regular expression syntax.  You wouldn't think that [[abc] would be valid, but it is.  You don't have to escape the opening bracket inside the character class.  So now the analyzer interprets this as it should. I've also fixed bugs around interpreting the \x00 (hex), \u0000 (unicode), and \k<group>  (backreference) expressions. P.S. The major updates I mentioned recently are still in the works.  So the price for Regex Hero Professional is still $20 for now.