Check regex Websites
regexpal.com
regex tester - javascript, pcre, php
regex.info
jeffrey friedl's web sites
regular-expressions.info
regular-expressions.info - regex tutorial, examples and reference - regexp patterns
regextester.com
regex tester and debugger online - javascript, pcre, php
debuggex.com
debuggex: online visual regex tester. javascript, python, and pcre.