1. Tuesday, September 11, 2007 9:04:47 PM by Jim Welch
    Thanks! Nice tool. Maybe you could incorporate some nice ajax callbacks to search regexlib's web service? ( Then it'll be nearly perfect. :)
  2. Tuesday, September 11, 2007 9:16:13 PM by Derek
    That's a great idea, Jim -- I'll look into it.
  3. Wednesday, September 12, 2007 3:07:25 PM by jhunter
    Have you considered releasing the source for this so someone can create a windows forms version easily?
  4. Wednesday, September 19, 2007 9:17:20 AM by Fabrice
    jhunter, there are already several Windows Forms tools for testing regular expressions. See
  5. Thursday, September 27, 2007 8:48:46 PM by bkhvihvbijhb
    I don't think you can call something "better" without supplying some sort of test results. What is yours better than?
  6. Thursday, October 04, 2007 5:15:39 PM by Aleksey Malishkin
    This is the greatest thing in the world! THANKS!!!!
  7. Friday, January 25, 2008 2:06:56 PM by Hue Holleran
    Really useful, Derek - the best around. Could I request one addition, please: could you add the group name to the output please? ie. pattern:@"--\s*\[\s*TABLE\s*\(\s*(?<table>.*?)\s*\)\s*\]", text:"-- [ TaBle ( bob ) ]" - I'd like to see the captured group name - would you consider doing this, please?
  8. Wednesday, February 06, 2008 1:04:00 PM by Poor Richard
    Works great. Just would like to see the results without having to scrool down (at least on my screen).

    Thanks. -- Richard
  9. Wednesday, February 06, 2008 1:08:39 PM by Poor Richard
    Oops! My mistake. You just need to scroll down once and it all stays on screen.

    Great! -- Rik

    PS: Nice if you either underline the matches or made them bold or red.
  10. Thursday, February 21, 2008 9:35:43 PM by LeeK
    Just perfect Derek - it's bookmarked for me now. Thanks 1,000,000.
  11. Monday, March 24, 2008 11:49:51 PM by Anonymous
    Hi, great regexp tester, thanks! I was trying to figure out why my matches weren't working, then I realized I was cutting and pasting text from Notepad into the Pattern section which includes a newline. Since my input didn't include a newline, the match failed.
  12. Wednesday, April 09, 2008 1:04:57 PM by sky
    multiline and singleline are mutually exclusive. they have nothing to do with how many lines are in the target. multiline off set the eol and bol anchors to match eof and bof. singleline on lets . match all characters including /n

    good luck.
  13. Wednesday, April 09, 2008 1:05:32 PM by sky
    OOPS - meant NOT mutually exclusive
  14. Monday, May 05, 2008 7:52:48 PM by Yakko Warner
    Echoing sky's comment. I actually had a situation that was solved (thanks to a MS MVP in an MSDN forum) by setting both SingleLine *and* MultiLine at the same time. So it does have its purpose.
  15. Friday, May 30, 2008 10:24:34 AM by Rob
    been looking for one of these for ages. Really nice work.
  16. Friday, June 13, 2008 7:10:24 PM by sahil
    I was testing with the regex class in .net 2.0 using c# and my regex and source would not give me a match. This tool does give me a match. Any Ideas?
    Great tool though, i must add.
  17. Tuesday, July 22, 2008 3:24:27 PM by Walter
    Thanks for this one. Saved my day!
  18. Sunday, August 03, 2008 5:18:48 PM by Alexander BH
    Thanks for this great tool. I use it all the time! I just wanted to let you know!
  19. Friday, August 15, 2008 10:33:48 AM by Emm
    This helped me a lot! Much appreciated!
  20. Saturday, August 16, 2008 7:53:54 AM by James
    Super handy! Thanks very much!
  21. Wednesday, September 17, 2008 10:03:33 PM by Robert S.
    Well done!
  22. Wednesday, November 12, 2008 11:53:20 AM by nyk_is_syk
    helped me when mattered. tx god bless u all.
  23. Tuesday, December 30, 2008 4:29:43 PM by Mike
    Thank You
  24. Wednesday, December 31, 2008 10:29:57 PM by Daniel
    This is a great tool, and I really appreciate your taking the time to put it together. I noticed that there seems to be a problem displaying captured groups. Try this pattern:


    with this string:

    This is one part.|This is another part.|

    This expression correctly captures both parts (I checked), but it displays the two groups as "This is another part.|" and "This is another part." when the captures are actually "This is one part." and "This is another part."

    Thanks again. This is an incredibly helpful tool!
  25. Monday, January 12, 2009 5:41:27 PM by Marcelo
    Very useful!
  26. Friday, January 16, 2009 12:45:08 AM by jeff
    Thank you! I use this a lot.
  27. Friday, January 16, 2009 1:12:08 PM by Marco
    Very useful :)
  28. Tuesday, January 20, 2009 8:58:01 PM by Matt
    @Daniel ^
    careful with your captures. The normal parenthesis are also captures even though they are not named.
  29. Monday, February 02, 2009 5:43:39 PM by Alan
    Very useful, thanks.
  30. Monday, February 02, 2009 6:43:56 PM by John
    Good job; thanks. Have you considered implementing non-greedy options? Or am I mistaken?
  31. Monday, February 02, 2009 7:39:34 PM by John
    Nevermind; my mistake.
  32. Tuesday, February 03, 2009 4:17:45 PM by Bill
    I love this app. Much nicer than the other online apps I used. Thank you much.
  33. Thursday, February 05, 2009 9:39:14 AM by Sireesh Jindal
    Hey, Is there any limitation in .Net regex on the input string?
    I have a 438 line input string, which I have to test against a Regex. But, in VS2005, everything seems to hang when I try to match the string with the Regex.
  34. Wednesday, February 11, 2009 3:35:48 PM by ADovervik
    If Visual Studio appears to hang for more than a second or two, you probably want to debug the regexp.

    I have tested (in VS2005) to run a fairly complex pattern with 36 capturing groups, and 358 non-capturing used for manging sections of the Regex, against a 300 000 lines text file. A couple of seconds delay, but no hang.
  35. Thursday, February 12, 2009 5:07:01 PM by LarryK
    This rocks ... thanks!!
  36. Tuesday, February 24, 2009 3:52:34 PM by Feng
    It is wonderful, save time, save life! Thanks a lot!
  37. Wednesday, February 25, 2009 8:02:05 PM by Jared Saindon
    FINALLY someone took the time to make a decent online regex tester. Your contribution to the programming world is much appreciated. You are the man!
  38. Tuesday, March 03, 2009 3:11:16 PM by BryanS
    AWESOME! Thank you, I've bookmarked this for validating my regex expressions.
  39. Tuesday, March 17, 2009 2:36:11 PM by Matt
    Fantastic tool, thanks!
  40. Tuesday, March 31, 2009 6:43:39 PM by Digant
    Awesome tool, use it so often. One thing I'd love to see is named capturing
  41. Tuesday, April 21, 2009 1:30:53 PM by Rajesh Pillai
    Good work.
  42. Thursday, May 07, 2009 12:38:18 PM by Klinkby
    I use the tool frequently. May I suggest a final touch? Print out group name for each capture. Thanks again!
  43. Saturday, June 06, 2009 6:10:54 PM by casey
    fantastic tool I like it much better than the clunky regulator
  44. Tuesday, June 16, 2009 11:56:59 PM by tertz
    nice tool!
  45. Thursday, June 18, 2009 12:18:54 PM by Alexander P
    Very practical tool! Thanks a lot
  46. Saturday, June 20, 2009 6:47:03 AM by Szczawik.PSq
    If I could recommend something: don't show additional quotation marks around matches as they may be confused as a part of a string (or simply show them i.e. in light gray colour).

    I usually don't bookmark any pages, but this one is worth it. What a nice and useful tool! Thanks!
  47. Friday, July 10, 2009 5:25:49 PM by Katie
    This is super helpful! Thanks! ^D'd!
  48. Thursday, July 30, 2009 7:21:14 AM by Marty
    Really great, thank you. Consider publishing source. It is surely highly appreciated. Regards.
  49. Friday, July 31, 2009 1:34:22 PM by James Shumaker
    Fantastic site, finally what I needed without all the hassle ;)
  50. Wednesday, August 05, 2009 9:36:49 AM by Dan Osborne
    Perfect, thanks!
  51. Wednesday, August 05, 2009 3:57:08 PM by Jason Abbott
    I think there may be an issue with the use of AJAX to transmit non-printing characters. If I try to match (the quoted character is 001A or SUB)

    Conversion from string "" to type 'Short'



    it fails here. But that same match succeeds in my code.
  52. Thursday, August 06, 2009 11:08:07 PM by InterPat
    Awesome thanks, very usefull
  53. Sunday, August 23, 2009 7:54:07 AM by strager
    Thank you for this! This is a very useful tool.
  54. Thursday, September 03, 2009 11:59:51 AM by Peter
  55. Monday, September 07, 2009 2:28:21 AM by Terrence
    I found (the hard way) that if multiple capturing groups are included, only the Groups are displayed in the output. The captures contained within the groups are not shown.
  56. Monday, September 07, 2009 3:45:24 PM by Stuart Duncan
    You might want to remove post number 54! lol

    Great tool, btw
  57. Friday, September 11, 2009 2:54:38 AM by s0beit
    Cool, can you add C++ output style as well?
  58. Thursday, October 01, 2009 4:14:02 PM by Rusty I've found on the web. Very helpful!
  59. Friday, October 09, 2009 5:33:41 PM by Gary
    Found a bug. HTML truncates a series of spaces to one
    space. Thus the result is displayed incorrectly when spaces are grouped. Consider non-breaking spaces or the 'pre' tag.
  60. Monday, October 26, 2009 3:40:37 PM by Brian
    I especially like how this tool provides all the character escaping for you. I'm generally too lazy to do any such thing myself and really can save some headaches for any super complex expressions... Thanks!
  61. Wednesday, November 11, 2009 6:56:33 PM by Gary
    Space bug still exists. Type "123", ten spaces, "ABC" in the Source text box. Then type reg exp "3\x20{10}A" in the Pattern text box. The result only shows one space rather than the 10 spaces. This is because of the HTML feature of truncating spaces to a single space.
  62. Saturday, November 14, 2009 1:34:58 PM by ForkandBeard
    Thank you for helping to take the sting out of Regex dev.
  63. Monday, November 23, 2009 11:44:16 PM by James
    Thank you. This was very helpful.
  64. Wednesday, January 06, 2010 5:08:13 PM by Evan
    I've had this bookmarked for over a year now, using it consistently. Thanks!
  65. Wednesday, January 13, 2010 1:25:45 PM by Salvatore aka ArtyProg
    many thanks for this very useful tool
  66. Wednesday, January 20, 2010 10:08:45 PM by P-KoS
    Really nice tool, I found it really helpful, thanks a lot.
  67. Tuesday, February 02, 2010 7:31:48 PM by Joe Vijay
    M-x regex-builder
  68. Thursday, February 11, 2010 2:15:43 PM by r3bb
    A life saver! Thank you very much!
  69. Monday, February 22, 2010 4:29:38 PM by Harry
    Thank you for your hard work and sharing attitude.
  70. Wednesday, March 03, 2010 12:33:08 PM by matthias
    Good work mate! Thank you...
  71. Friday, March 05, 2010 9:42:06 AM by Thomas
    Super! Uses this all the time...
  72. Thursday, March 25, 2010 9:55:39 PM by Me
    I have a regular expression that matches URLs but strangely kills .NET (and this site) when testing on a URL with a - int he query string. I found this out from a user that copied an Amazon link.

    I would have expected 0 matches not .NET to crash if the expression was an issue.

    Here is the expression:

    Here is a sample that crashes it:

    If you change the input to this it matches and does not crash:

    How can this be fixed? Is it a .NET bug?
  73. Thursday, April 08, 2010 12:06:16 PM by Antonis
    Great work. Fast and lightweight! Thanks
  74. Monday, April 12, 2010 6:55:14 PM by Mr. Albright
    I use this all the time. Thanks!
  75. Friday, April 16, 2010 12:40:48 PM by SML
    Bookmarked and much appreciated!
  76. Wednesday, May 05, 2010 1:19:53 PM by Mr. Waugh
    I use this all the time too! Just thought I'd show my appreciation.
  77. Friday, May 07, 2010 7:11:54 PM by Aleksey Malishkin
    Did I mention just how useful this is. Thank you so so so so much!!
  78. Sunday, May 09, 2010 1:55:51 PM by Andrew Gibson
    Awesome. Why don't people do simple, easy stuff?
  79. Monday, May 10, 2010 9:00:09 AM by Rob
    Heel mooi!
  80. Tuesday, May 18, 2010 9:07:36 PM by maltezefalkon
    Fantastic tool. I use it nearly every day it seems... Great work!
  81. Wednesday, May 19, 2010 4:35:52 AM by herry
    I've used your tool for a while and haven't said thank you yet.
    How slack of me.
    Anyways, great tool, love it, please please never put it down.
  82. Wednesday, June 02, 2010 2:28:17 PM by Rui Domingos Ferreira
    Thanks a lot, very usefull :)
  83. Monday, June 07, 2010 6:42:25 PM by Suraj
    Thanks a ton, you made my day...
  84. Tuesday, June 22, 2010 6:29:53 AM by Mkr
    Found a similar one here, ability to name groups kinda rocks! =)
  85. Wednesday, June 30, 2010 10:14:47 AM by shinuq
    just classy... liked that
  86. Thursday, July 08, 2010 7:43:14 PM by Robert A. McCarter
    Thank you very much!
  87. Tuesday, July 13, 2010 6:37:33 PM by Naeem
    Use this site every once in a while, great help.

    Thank you.
  88. Wednesday, August 04, 2010 12:13:59 PM by Seema
    hey...thxs a lot.
    Its really a good tool...Great work
  89. Friday, August 06, 2010 9:35:17 AM by tester133
    Really cool and pretty tool! Thx a lot!
  90. Wednesday, August 11, 2010 7:35:45 PM by John Ruiz
    Thank you for this. I was going to write a little app myself but then I realized that someone had to have done it already!
  91. Sunday, September 12, 2010 1:10:10 AM by Brian
    Just wanted to thank you for this tool! Works great!
  92. Wednesday, September 22, 2010 7:19:30 AM by Ajith Kumar
    Thank you so much! I was never in good terms with RegEx, but this tool made them so easy...
  93. Monday, October 04, 2010 12:03:51 PM by Tal
    Derek, thank you very very much for keeping this up. It's been extremely helpful to me.
  94. Monday, October 04, 2010 11:43:52 PM by Daryl Blowes
    Figuring out the RegEx.Replace behavior is a little different than the Match behavior ... It would be nice to see another button for the Replace function and see the result.
  95. Saturday, October 23, 2010 7:40:12 PM by Ignignokt
    This is so much more convenient than the hacked up winforms tester I wrote to evaluate my regex.
  96. Monday, October 25, 2010 9:57:12 AM by Dave
    This is great, thanks!!
  97. Monday, October 25, 2010 4:50:05 PM by Robert McCarter
    Thank you!! Very useful.
  98. Monday, October 25, 2010 7:10:09 PM by Shimmy
    Great job Derek
  99. Thursday, November 11, 2010 12:26:31 PM by Noam Gal
    Thanks - just used your site to debug a regex from hell. Been very helpful.
  100. Monday, November 22, 2010 4:51:15 PM by Kurt Griffiths
    Thanks for finally writing a simple online tester that even shows the escaped C# string!
  101. Friday, November 26, 2010 7:14:41 AM by Steve Trefethen
    Thanks! Allowed me to quickly find/fix a bug in my facebook application that maps your friends:
  102. Tuesday, November 30, 2010 10:00:06 PM by michel
  103. Tuesday, December 14, 2010 12:56:31 PM by progtiem
    Excellent resource! I hate figuring these things out directly in VS while running the program.
  104. Tuesday, December 14, 2010 3:05:40 PM by Serge Weinstock
    Thanks, it's very useful
  105. Friday, December 17, 2010 6:22:54 AM by LT
    Thanks for the great tool. Your kung-fu is strong!
  106. Sunday, December 19, 2010 3:40:01 PM by Pawel Czopowik
    Just what i needed! Thanks!
  107. Thursday, December 30, 2010 5:29:25 AM by John Melville
    Use this all the time, thank you for hosting such a useful tool.
  108. Saturday, February 05, 2011 4:47:50 PM by Bartosz Bielecki
    Very useful tool!
  109. Wednesday, February 09, 2011 2:12:15 PM by Charlie
    Very convenient tool, thank you
  110. Sunday, February 20, 2011 8:17:39 PM by Triscopic
    FYI, I use this tool a lot... but I've never actually said thank you. Sorry for my bad manners, thanks for this quick, handy and powerful tool.

    Captcha: Mutation Mustard. made me laugh!
  111. Tuesday, February 22, 2011 10:33:25 AM by Max
    This pattern: ^(((?<1>[^,]{3,6})|([^,]*))(,|$))*
    With ExplicitCapture
    With this source: AA,BB&B,!CC,DDDDDD,EE

    Gives only one capture. It should give 3 captures BB&B,!CC,DDDDDD
  112. Wednesday, February 23, 2011 1:04:59 PM by Mohammad Ashour
    Awesome little tool! Thank you!
  113. Saturday, February 26, 2011 3:36:16 PM by Antonio T.
    Grate, thank you very much
  114. Wednesday, March 02, 2011 11:39:07 AM by David
    Great tool, have it bookmarked, use it all the time I'm creating regexes. Thanks!
  115. Thursday, March 03, 2011 12:10:42 AM by Mike B.
    Thanks! Works splendidly.
  116. Friday, March 11, 2011 2:29:28 AM by Shiroy
    Fantastic!! This is a simple and awesome tool!
  117. Friday, March 11, 2011 4:12:48 AM by Chaitanya
    Currently as on March 11 2011, The RegEx Tester seems to be not working. It would be great idea to make an utility, Since the tool is wonderful and deserve survival and existance.
    Will be happy if available at the earliest (atleast the link revives it will be great)
  118. Tuesday, March 15, 2011 6:18:50 PM by Shawn
    Thank you SOOOOO much for making this available. Every time I needed something like this I had to write a small test app because I'd lose the last one I wrote.
  119. Wednesday, March 30, 2011 8:01:39 PM by Dzyann
    I was having problems with a regex, and after looking all over the place, I found this place and finally could make it work! Thanks!
  120. Friday, April 29, 2011 2:30:33 PM by Rajeve
    Thanks, good app - what's with the Russian comments??
  121. Tuesday, May 03, 2011 11:35:22 AM by Fredrik
  122. Monday, May 09, 2011 11:14:34 AM by Ajeesh
    Thanks, nice work.

    I am facing problem with the following regular expression. I was trying to find out repeating pattern in the input string.

    Input String : 1234123412341234
    Pattern : ^(.*?)\1+

    It is working on, but some how it is not working with .NET regex. Could u pls help me to figure out the exact problem?

    Thanks for your valuable time.
  123. Wednesday, May 11, 2011 8:34:44 PM by mr proper
    This is nice tool. Working and fast.
    For larger texts I would also recommend
  124. Thursday, June 30, 2011 12:25:01 PM by Zul
  125. Thursday, July 07, 2011 1:18:13 PM by Culme
    Thanks, this was useful!
  126. Wednesday, July 13, 2011 8:52:56 AM by paulg
    very useful, saved hours! However, doesnt seem to work in chrome! But does work fine in internet explorer
  127. Friday, July 29, 2011 3:24:43 PM by Mark
    This is wonderful utility! Thank you. (By the way, it works fine in Chrome [version 13.0.782.107] for me. )
  128. Friday, August 05, 2011 8:41:38 PM by whiterabbit
    It would be great to be able to "Regex.Escape" the input string. :)
  129. Sunday, August 07, 2011 9:21:36 PM by Marco
    So simple, but so great... Thanks!
  130. Thursday, August 18, 2011 8:04:15 PM by Daniel
    Thanks Derek. Huge time saver.
  131. Thursday, August 25, 2011 9:44:13 AM by orest
  132. Wednesday, August 31, 2011 10:29:07 PM by Ketcher
    This was very helpful, thank you!
  133. Tuesday, September 20, 2011 12:27:46 PM by Guy
    Great tool, 10x :-)
  134. Sunday, September 25, 2011 2:10:28 PM by Diego
    Simple and useful tool, thank you!
  135. Thursday, September 29, 2011 9:34:25 PM by Rod
    I needed to build a .NET regex today and this was very handy; ty. It works fine for me in Chrome (14.0.835.186).

    If I might sneak in a feature request, it would be nice to have the results update "live"; eg as I type instead of having to click the apply button.
  136. Wednesday, October 12, 2011 9:41:40 AM by Olek
    It's great, thank you
  137. Wednesday, October 26, 2011 11:54:58 AM by Dmitry
  138. Sunday, December 04, 2011 11:08:05 PM by AlexRsk
    It seems that multiline option is not working. Please test it
  139. Wednesday, December 07, 2011 9:27:05 AM by CodeRookie
    Very nice tools, extremely helpful for application development.

    Great work.

    One piece of example:
    Matching all entities to be included in EF-Query: Regex.Matches(expr.ToString(), "([^=]+)\s*=>\s*\1\.([^\)\.]+)") :-)
  140. Sunday, January 29, 2012 4:23:36 AM by Steve
    Great work! I've used it a lot! It actually inspired me to build a similar one in silverlight:
  141. Wednesday, February 08, 2012 5:35:26 PM by EACCoder
    I keep getting the following error when I try to use this page: Line: 133
    Error: 'urchinTracker' is undefined
  142. Friday, February 10, 2012 9:37:07 AM by Shannon Alleyne
    Great job. Your creation will be useful for many generation to come. Cheers!
  143. Friday, February 10, 2012 7:51:49 PM by Ruben
    Thank you very much for you site. How many sites are still heavily used after such a long time.
  144. Friday, February 24, 2012 8:40:43 PM by Doug
    I come to this page at least once a month for the past 3 years... have to say it's a pretty great tool.
  145. Thursday, March 01, 2012 5:03:31 PM by Barton
    I've been looking for one of these for ages. Really nice work!
  146. Friday, March 09, 2012 12:42:25 PM by matthias
    2 years and 6 days ago, i already posted here and i again want to tell you, that this expression tester is awesome :)
    true, i use it in a completely different context now, but still the best out there :)
  147. Wednesday, March 14, 2012 3:54:56 PM by misha amashukeli
    Very good tool, helped me several times. Thank you!
  148. Friday, March 23, 2012 6:38:19 PM by Corporate Serf
    2012 and still a tool I use regularly.

    You should put a Donate button on the page ;)!
  149. Thursday, April 05, 2012 8:13:00 AM by Bart
    I love this tool. Tnx!
  150. Wednesday, May 02, 2012 4:13:20 AM by D Gorti
    Thank you!!!!!
  151. Wednesday, May 02, 2012 11:49:01 AM by Shim Shim
    This is wonderful! Thank you!!
  152. Thursday, May 03, 2012 2:44:39 PM by Andrew Day
    Hey guys I hope you can help I am trying to build an regx that will validate all email address except for one specific domain an I want to use this in the c# regx validation control

    any ideas?
  153. Tuesday, May 08, 2012 11:03:51 AM by Jack
    Very useful tool. Thanks a lot!
  154. Thursday, May 10, 2012 4:03:01 AM by auraham
    thanks, very useful
  155. Saturday, May 12, 2012 10:33:35 AM by arvi
    really great tool.
  156. Wednesday, May 23, 2012 6:34:55 PM by Cory
    I can't tell you how many times I've used this tool. Thanks.
  157. Saturday, June 02, 2012 7:35:34 AM by Keen
    Thank you for taking the time to do this and for making it freely available to others.
  158. Thursday, June 07, 2012 3:40:37 PM by Billy
    NICE !!! Thanks !!!
  159. Monday, June 11, 2012 10:28:36 AM by Nir
    Thank you very much for this awesome tool!
  160. Friday, June 22, 2012 2:35:30 PM by Nathan
    Use it all the time. Love it.
  161. Sunday, July 01, 2012 4:06:38 AM by David
    Very nice. I particularly like the enumeration of the matched groups.
  162. Tuesday, July 03, 2012 12:44:46 PM by Mike Harper
    Excellent, solved my problem quickly and easily. Bookmarked for future reference. Thank you.
  163. Monday, July 09, 2012 5:38:05 PM by Joel C.
    Good stuff, thanks!
  164. Monday, July 23, 2012 10:20:17 AM by <3 u
    <3 u
  165. Monday, July 23, 2012 7:41:40 PM by Steve F
    Very useful, thanks!
  166. Tuesday, July 24, 2012 8:24:44 AM by Ranjith
    Very userful.. Thanks alot
  167. Thursday, July 26, 2012 1:09:43 AM by M
    Any chance I can have your babies?
  168. Thursday, July 26, 2012 4:03:22 AM by M
    Not like to eat or anything, that would be weird.
  169. Friday, July 27, 2012 8:46:57 AM by AnimeshB
    This is very useful. Thanks!
  170. Monday, July 30, 2012 9:19:47 AM by InformaticaFunction
    Very nice utility.
  171. Monday, August 06, 2012 11:13:19 AM by Lucas
    That is awesome. Thanks.
  172. Tuesday, August 07, 2012 10:00:54 PM by Keith B
  173. Saturday, September 01, 2012 1:48:56 AM by Egor
    Thank you
  174. Friday, September 14, 2012 3:33:14 AM by Dr F
    This is the best thing that anybody's ever done ever.
  175. Friday, September 21, 2012 4:48:49 AM by Corey
    Nice, and very useful.

    One suggestion though... I often use .NET regular expressions with repeated captures, and so far none of the regex testers I've seen give me any feedback on the number of captures.

    For example, IP address mask testing:

    Pattern: ^((?:(\d+)\.?)+)/(\d+)$

    Match group 2 is shown only as '192' when it has 4 captures, one for each part of the address.

    Adding support for displaying those would be extremely helpful, not to mention TOTALLY awesome.
  176. Wednesday, September 26, 2012 8:01:28 PM by passerby
  177. Thursday, October 04, 2012 2:21:15 PM by Jam
    Thanks from France for your tool !
  178. Monday, October 08, 2012 2:51:26 PM by Diane
    Thank you for this tool. Being able to test the actual regex engine that I'm writing for has been extraordinarily helpful.
  179. Thursday, October 11, 2012 9:04:52 PM by Andrew
    Derek, I find myself always using your tool when I have to delve into .NET Regex. Thank you!
  180. Thursday, November 15, 2012 12:47:39 AM by Gordon MacDonald
    This is a "Must Have" tool. Thanks so much!
  181. Tuesday, November 27, 2012 10:49:15 PM by Niklas
    Thanks SO much for this tool! I'm using it almost every day. It's just perfect!

    You made my live easier!
  182. Saturday, December 08, 2012 5:20:39 PM by seba
    Derek seem to doesn't evolve this tester, so maybe you wanna try this one: ?
  183. Friday, December 21, 2012 2:40:33 PM by Gareth
    Very useful testing tool, cheers!
  184. Monday, December 31, 2012 1:43:24 PM by bob85
    Fantastic!! From Italy a big thanks...and a happy new year :)
  185. Monday, December 31, 2012 2:50:02 PM by bob85
    Fantastic!! From Italy a big thanks...and a happy new year :)
  186. Friday, January 25, 2013 4:03:31 PM by achand
    This is my go to resource for all things Regex.NET. Thank you for this!
  187. Friday, February 08, 2013 5:22:58 AM by Kevin R. Beck
    Well this is ok, but it's clear that you're using the wrong type of soil for your potatos. I recommend loam.
  188. Tuesday, February 12, 2013 6:30:57 PM by delta
    Cracking! Thanks straight in there
  189. Wednesday, February 20, 2013 1:15:25 PM by Marcus
    Great stuff, very helpful and productive , thanks from Germany.
  190. Wednesday, February 27, 2013 6:13:23 PM by eMartin
    May your children be fertile.
  191. Wednesday, March 13, 2013 5:11:40 AM by eMartin
    May you forever be able to find a little scrap of paper to write something down on real quick whenever you need one.
  192. Thursday, March 14, 2013 1:33:48 AM by eMartin
    If you disable the ipc$ share, WINDOWS will automatically re-enable it upon next boot. So, you can set a batch file to start up with your system to take care of that.
  193. Monday, March 25, 2013 9:59:02 AM by Carles
    Great Tool, Very very thanks Derek ;)
  194. Tuesday, March 26, 2013 8:28:10 PM by Radek
    I was jus going to write a regex tester myself. No need to do so. Thanks!
  195. Tuesday, April 02, 2013 4:13:22 AM by Kevin R. Beck
    I was jus going to write a regex tester myself. No need to do so. Thanks!
  196. Wednesday, April 03, 2013 5:45:02 PM by Andrew
    If source contains any #-specific escapes (i.e ), they are being decoded before being applied to the regex.
  197. Wednesday, April 03, 2013 5:45:35 PM by Andrew
    See above^, & 3 2 ;
  198. Wednesday, April 03, 2013 5:45:50 PM by Andrew
    & # 3 2 ;
  199. Saturday, April 06, 2013 6:22:11 AM by Aneeth
    Show matches
  200. Wednesday, April 17, 2013 1:39:12 PM by Fernando Torres
    Very helpfull. I've been using it so much. Tks!
  201. Friday, May 10, 2013 6:54:22 PM by Eric
    A regex cheat sheet would be a welcome addition
  202. Tuesday, May 14, 2013 5:37:30 AM by Kevin R. Beck
    Very helpfull. I've been using it so much. Tks! A regex cheat sheet would be a welcome addition.
  203. Wednesday, June 19, 2013 11:07:23 AM by Kemal
    Thank You, Derek!
  204. Friday, June 28, 2013 7:52:33 AM by Andrey
    Thank you very much.
  205. Friday, July 05, 2013 11:18:13 PM by Phil
    Thanks a lot, very useful.
  206. Saturday, July 06, 2013 5:54:59 PM by Phil
    Thanks a lot, very useful.
  207. Tuesday, August 06, 2013 12:37:50 PM by Igor
    Thanks a lot!
  208. Wednesday, August 07, 2013 10:30:20 PM by Alexandr
  209. Wednesday, August 28, 2013 3:33:15 PM by Matthew
    I agree with Terrence, Max, and Corey. It would be really nice if this could include the captures, not just the groups.
  210. Monday, September 09, 2013 8:20:01 AM by Liam
  211. Thursday, September 12, 2013 12:14:00 PM by David S
    Thank you. This is by far the best regex engine I could find in the net. Thanks a lot!
  212. Saturday, September 14, 2013 12:05:21 AM by Me
    Thanks for hosting this
  213. Thursday, October 03, 2013 9:52:53 PM by Justin
    You should add support for CRLF source. It works great if your source is always LF only.
  214. Friday, October 25, 2013 10:44:15 PM by I
    Keep coming back to useful!
  215. Wednesday, November 13, 2013 6:47:59 PM by Mark
    You, Sir, do so both rocketh and rolleth! Thanks for making such a handy utility available.
  216. Thursday, November 28, 2013 6:43:47 AM by Honza
    Nice work! Thanks.
  217. Thursday, December 19, 2013 9:16:08 AM by Rainer
    I have a problem with special Letters like hex(c2) my regex doesn't find that this is not allowed:
  218. Thursday, December 26, 2013 8:56:06 AM by Bo
    Awesome tool. Thanks a lot for sharing!
  219. Thursday, February 06, 2014 6:40:31 AM by Random guy
    Thanks for creating such a useful site good job. You made learning Regex a LOT easier.
  220. Monday, February 17, 2014 11:57:09 PM by Tim
    Thanks - very helpful tool :)
  221. Wednesday, February 19, 2014 12:53:40 AM by The Zoner
    Thank you for this!!
  222. Thursday, March 20, 2014 3:27:58 PM by Esteban
  223. Tuesday, April 01, 2014 1:55:05 PM by Rob
    You Rock!!!
  224. Friday, April 25, 2014 11:21:30 PM by Preetham Reddy
    It just helped me understand why one RegEx pattern isn't matching.
  225. Wednesday, April 30, 2014 11:29:10 AM by ahmedsafan86
    Thanks alot, this is a simple helpful and fast tool, thanks a lot
  226. Wednesday, April 30, 2014 6:33:30 PM by Syed
    Very helpful... TY!
  227. Thursday, May 08, 2014 5:29:13 AM by jonbakari
    live saver! thanks so much.
  228. Friday, May 09, 2014 2:51:43 AM by Maureen
    Thank you so much!
  229. Monday, May 12, 2014 5:22:52 PM by jonbakari
    live saver! thanks so much.
  230. Friday, May 30, 2014 6:58:05 PM by Tony Chung
    This tool is incredible. Thanks!
  231. Wednesday, June 04, 2014 11:01:05 AM by Bipin
    Thanks! bookmarked now :)
  232. Tuesday, July 08, 2014 3:57:36 PM by Rob
    Love it !

    Why has it taken me so long to find it. Lost count of the number of times I needed something like this.
  233. Tuesday, July 22, 2014 5:56:25 AM by Uwe
    The first hit on Google and also the best online tool out there since Regulator seems to not work on Win 8.1 anymore.
  234. Saturday, August 02, 2014 4:45:19 AM by Scott Smith
    Just wanted to say thanks. This page has come in handy more times than I can count. Well done.
  235. Friday, August 15, 2014 8:12:59 PM by Broken Event
    Also wanted to say thanks. This page is almost all I need when working with .NET regexes.
  236. Wednesday, August 20, 2014 3:08:21 PM by mrkasr
    great tool , i love it.
  237. Thursday, September 04, 2014 8:15:06 AM by hebbja
    Simple live saver. Thank you
  238. Friday, September 12, 2014 8:08:40 AM by Volodymyr Knayzkov
    It is great tool. Thank you for your work
  239. Wednesday, September 24, 2014 9:04:56 AM by schleeke
    nice one - helped me a lot while validating my patterns, thanks! :)
  240. Monday, September 29, 2014 4:27:55 PM by Mauricio Bustamante
    Hi, great tool. I've been using it for a long time but now I need to do something that I don't want to using c#. Is it possible to get the number of times a word is repeated in a sentence: e.g. Sentence: "abc abc abc" Regex: ((?i)\babc\b). I want to get 3 instead of using .Count or Linq?
  241. Wednesday, October 22, 2014 8:27:39 PM by Tuan
    Great tool! Simple yet incredibly useful!
  242. Saturday, November 15, 2014 5:06:06 PM by Luis Marin
    This page of yours is a nice page: simple, straightforward. A couple of hours a go I've created somehing alike in VB.Net... :P
  243. Saturday, November 22, 2014 6:56:29 PM by James Rolan
    Great for .NET user. For people who need some PHP or Ruby regular expression tester, you can try It's okay.
  244. Monday, January 19, 2015 7:09:53 PM by Mark K
    Still one of the best (if not the best) tools out there for quickly double-checking regular expressions in my code.

    Thank you for sharing!!!
  245. Tuesday, February 10, 2015 3:48:14 AM by kaka
    This is a nice and informative, containing all information and also has a great impact on the new technology. Thanks for sharing itPoker OnlinePoker Online IndonesiaPokerGame Poker IndonesiaPoker Online AsiaAgen PokerCasino Online
  246. Monday, February 16, 2015 5:03:08 PM by Brad Herder
    Super helpful! Thanks!
  247. Tuesday, April 07, 2015 10:20:02 AM by Pedxriton
    Thank you Derek, you are my hero.
  248. Wednesday, May 20, 2015 1:25:22 PM by Ellen
    so helpful thanks!!
  249. Friday, September 18, 2015 1:37:10 PM by Dmitry
    Good, but i use this: online .net regex tester for .NET c# and regex debugger \m/
  250. Tuesday, October 13, 2015 6:35:38 PM by blahpers
    Thanks for this! I believe that I also found the ad-covered site of which you speak. It was awful.
  251. Monday, October 26, 2015 12:46:15 PM by onder
    Using this page for 2 or more years.

    Every day, I pray gods for:
    1- Not losing this site url.
    2- Not seeing this site down.
  252. Tuesday, October 27, 2015 11:36:19 PM by Jennifer
    Great tool! Thanks!
  253. Tuesday, November 10, 2015 11:39:09 AM by Colin
    Wish that I had found this sooner! Thanks.
  254. Monday, November 23, 2015 7:45:09 PM by EM
    Good Job!
  255. Thursday, December 17, 2015 11:14:50 PM by Aileen Morillo
    Practical analysis , Coincidentally , if you requires to merge are interested in merging of , my business discovered a tool
  256. Friday, January 08, 2016 7:47:10 PM by Justin
    I use this all the time for testing out regex, thanks Derek!
  257. Friday, February 05, 2016 12:32:13 AM by Riley
    My favorite regex tester
  258. Friday, February 05, 2016 6:00:45 PM by Mikhail Zaretski
    Thank you a lot
  259. Wednesday, February 10, 2016 8:13:02 PM by Randal Boggz
    Thanks! It is very helpful for me,
  260. Friday, February 26, 2016 7:23:53 AM by Sarunas
    Please add timeout, it is possible to crash your website with complex regex and bigger data set.
  261. Wednesday, June 15, 2016 5:51:41 PM by David Rogers
    Move over sliced bread!
  262. Wednesday, June 29, 2016 5:40:44 PM by Wesley
    I've been using this as my go-to regex tester for the past two years. It has been very helpful. Thank you! <3
  263. Tuesday, July 26, 2016 2:03:18 PM by Chad
    I love this tool. I use it often for development. Thank you so much for providing it for everyone!
  264. Friday, August 19, 2016 6:25:30 AM by Kevin R. Beck
    Chad loves this tool. He uses it often for development. Thank you so much for providing it for everyone!
  265. Friday, September 09, 2016 3:19:27 AM by SMR
    Excellent job.
  266. Wednesday, November 16, 2016 11:44:47 PM by Rui
    Thanks for bringing this tool back online. I use it frequently and was panicking that it went offline.
  267. Thursday, December 01, 2016 4:21:06 PM by Ruben OUDE TANKE
    Every time a need to build a regular expression, I return to this page.
    Thank you such much for making this available to everyone.
  268. Sunday, February 26, 2017 3:15:17 PM by jistme
    Thank you for this tool!
    Working great.
  269. Sunday, February 26, 2017 3:22:05 PM by jistme
    Thank you for this tool!
    Working great.
  270. Monday, April 24, 2017 5:58:36 PM by Paz
    nice tool
  271. Wednesday, August 09, 2017 12:56:38 AM by Kevin R. Beck
    I am a website
  272. Monday, September 18, 2017 5:44:12 PM by FishBasketGordo
    A little late, but happy 10th anniversary to this nice and simple regex tester. I still use it regularly.
  273. Wednesday, October 04, 2017 4:55:52 PM by Heber G. Junior
    Thank you for this tool!
    Helped me a lot today.
  274. Thursday, October 05, 2017 4:08:57 PM by Ben
    Still using it on a regular basis, thanks !
  275. Wednesday, November 22, 2017 12:13:54 PM by Dejan
    Excellent tool, thanks a lot!
  276. Friday, January 05, 2018 8:15:13 PM by Bekir
    I was studying regex in c#. This tool made me understand string literals. Thanks.
  277. Sunday, April 15, 2018 12:35:16 PM by Jenda
    Since .Net doesn't provide good syntactic support for regular expressions it would be good if the testing tool optionally accepted the regexp escaped as if in a "" or @"" string literal.
  278. Saturday, May 12, 2018 1:36:01 PM by Avi Farah

    Your tool is an awesome tool that I use often. It appears though that there is a discrepancy between .Net's handling of "$" with a Multiline (RegexOptions.Multiline) option and your handling.

    Your handling is the correct one but .Net treats $ the same with Multiline option and Singleline option.
  279. Monday, November 26, 2018 12:17:44 PM by Markus
    I use your tool for years now, thank you so much for this! It's the best :)
  280. Thursday, April 18, 2019 2:49:54 PM by Rodrigo Medina
    Thanks for this tool. The best! I'm using it for years.
  281. Thursday, July 11, 2019 6:08:30 AM by Mobile App Development Company Dubai
    Great post. Tools were really helpful, using them for quite a time now
  282. Thursday, September 05, 2019 4:28:44 AM by Ian Warro
    Still using this in 2019 ;) Thank you!
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