Regular Expression Tester

This page uses the regular expression parser in your browser's implementation of JavaScript.  This page should work with any browser that obeys the DOM, and Internet Explorer.*  If you're looking for a .NET Regex tester, there's a crackerjack one here.


Test String:



Original string:



[abc] A single character: a, b, or c
[^abc] Any single character but a, b, or c
[a-z] Any character in the range a-z
[a-zA-Z] Any character in the range a-z or A-Z (any alphabetical character)
\s Any whitespace character [ \t\n\r\f\v]
\S Any non-whitespace character [^ \t\n\r\f\v]
\d Any digit [0-9]
\D Any non-digit [^0-9]
\w Any word character [a-zA-Z0-9_]
\W Any non-word character [^a-zA-Z0-9_]
\b A word boundary between \w and \W
\B A position that is not a word boundary
| Alternation: matches either the subexpression to the left or to the right
() Grouping: group all together for repetition operators
^ Beginning of the string
$ End of the string
Repetition OperatorMeaning
{n,m} Match the previous item at least n times but no more than m times
{n,} Match the previous item n or more times
{n} Match exactly n occurrences of the previous item
? Match 0 or 1 occurrences of the previous item {0,1}
+ Match 1 or more occurrences of the previous item {1,}
* Match 0 or more occurrences of the previous item {0,}

g "Global" -- find all matches in the string rather than just the first
i "case Insensitive" -- ignore character case when matching
m "Multiline" -- search over more than one line if the text contains line breaks

By Rob Locher

Valid HTML 4.01! Valid CSS!

* The previous version of this page worked only with Internet Explorer.  I'm sorry if it caused you any inconvenience.

Another hack required for IE if ( match = Pattern.exec(document.getElementById("TestStrBox").value); else match = null; if (null != match) iMatchCount += 1; } if (1 == iMatchCount) Label("1 match found."); else Label("" + iMatchCount + " matches found."); } // Go() //-->