ReFiddle: Fiddle for Regexp testing (refiddle.com)

Awesome! I'm however unable to make negative lookaheads and lookbehinds work right now – though Ruby & .NET are said to support them according to http://en.wikipedia.org/wiki/Comparison_of_regular_expressio....

Rex V (http://www.rexv.org/) is my current favourite regex playground.

Would be great if there were support for more Regex types. All those supported by grep (ie. BRE, PRE, PCRE) seem fairly essential – and being a Python guy, Python would be nice too (which are PCRE-ish).

Nice work, though.

For a CLI debugger/play-through have a look at Regexp::Debugger (I posted this video link yesterday - http://news.ycombinator.com/item?id=4136179)

More contrast, please. I can barely see the green matches on my screen.

Nice work! :)

http://rubular.com is also a good one (Ruby regexes).

    (js|re)?Fiddles?

I'll go ahead and recommend RegexBuddy (http://www.regexbuddy.com/) as another useful tool for testing regexes. (No affiliation, this just happens to be one of the most useful programs I've bought with my own money.)

http://www.regexpal.com/ is a good alternative too

If you are looking for a command line regexp builder I highly recommend txt2regex. It is a giant bash script so it runs anywhere bash does and supports:

  a) +awk                                m) +mysql 
  b) +ed                                 n) +ooo 
  c) +egrep                              o) +perl 
  d) +emacs                              p) +php 
  e) +expect                             q) +postgres 
  f) +find                               r) +procmail 
  g) +gawk                               s) +python 
  h) +grep                               t) +sed 
  i) +javascript                         u) +tcl 
  j) +lex                                v) +vbscript 
  k) +lisp                               w) +vi 
  l) +mawk                               x) +vim 

http://aurelio.net/txt2regex/

My entry into this category:

http://regex.powertoy.org/

It makes use of a hidden Java applet -- so it supports the somewhat larger Java regex syntax, doesn't send your data anywhere else for matching, and can hook into the string-probing to animate the process. (Click the 'animate?' link to show the animation step/speed controls.)

For example, you can watch the regex that tests whether a number is prime (by failing) or composite (by succeeding) via these two animations:

49: http://regex.powertoy.org/?pat=/^1%3F%24|^%2811+%3F%29\1+%24...

47: http://regex.powertoy.org/?pat=/^1%3F%24|^%2811+%3F%29\1+%24...

Is the applet requirement a deal-breaker for casual use? I might be able to feed the OpenJDK 7 regex classes through the Google Java->JS cross-compiler to get a pure-JS solution with the same syntax/animation capabilities.

The best tools out there for regexp testing is http://gskinner.com/RegExr/ - the only flash application i've ever used

I've been using RegExr[1]. It's Flash/Flex, the "Community" tab is useful for finding common RegEx's.

[1] http://gskinner.com/RegExr

Cool! Is the code open source?

I use sublime text for this. Considering how many regexes I write a day, I actually need a text editor that has this support. Don't you ? :)

Some other online regex tools that you may find useful depending you what flavour of regex you want to create and how proficient you are with them:

• http://www.rexv.org/ — Supports: PCRE, Posix, Perl, Python, JS, Node.js modifiers. Only works online though.

• http://gskinner.com/RegExr/ — Implemented in Flash. Desktop version available.

• http://regexpal.com/ — Javascript regex only.

You are my hero.

I've used lots of regex tools over the years, but I stopped looking once I bought RegexBuddy.

See a demo: http://www.regexbuddy.com/demotest.html

It's a Windows program, but runs on Linux via WINE. It lets you debug regexes, has live highlighting of matched text, generates regex code in 15+ languages (Perl, Python, Ruby, PHP, C, C#, C++, Delphi, Java, Javascript, MySQL, etc) and is all around awesome.

I'm not affiliated with this program, but it is the BEST regex creation/testing program available anywhere.

It will save you oodles of time if you create (or debug) regular expressions more than 2 times in a year. It's the best software product I've ever bought with my own money.

If you work with .NET regex, I recommend http://regexhero.net/

Very nice, please add Java and Python support, but otherwise really dig it.. the tests are especially neat.

Nice work! It sure do got a purty mouth.

I too have a website that does regex testing. It supports Java, JavaScript, .Net, Perl, PHP, Python, Ruby & XRegExp, though some are more complete than others.

And it supports sharing & a cookbook too.

http://www.regexplanet.com/

I've always been a fan of Reginald (http://atastypixel.com/blog/reginald-regex-explorer/) on OS X.

This regex creator is one I've used for ages; its a bit ugly but it generates the regex for Perl PHP Python Java Javascript ColdFusion C C++ Ruby VB VBScript J#.net C#.net C++.net VB.net. You type an example (or the actual) string you plan to search over, click submit and it generates a weird chart that you can use to select which bits you want your regex to find. Really advise giving it ago; no regex knowledge required and more importantly.. fast.