Regular expression is a powerful way to target complicated URLs or to simplify complex conditions into a single query.

How does a regular expression (regex) work?

In regular expression you combine literal characters with special characters to create a logical pattern. This logical pattern then defines which URLs will be targeted and which will be out of scope.

  • Literal character = any character of your URL, such as "w" or "/" from ""
  • Special character = a character having special meaning, such as "\d" means represents any single digit

Please note, that some characters common in the URL (such as / or .) is by considered special by regex. Therefore if they are meant literally, it is necessary to always put "\" in front of them. The common URL will then look like "www\.examplepage\.com\/page".

Examples of regular expressions

Regular expressionURLs that will be targetedMore information
^www\.examplepage\.com$An exact match of

URLs containing specific pages (such as will be excluded!
^ signals that the URL must start there
$ signals that the URL must end there

All URLs containing "", then number of any length and then "/edit" will be targeted
\d represents any digit
+ signals the previous sign is present one or more times

Together (\d+) they mean one or more digits.
examplepage\.(com|net)Any URL containing or| signals that word before or word after needs to be there

The condition can be put inside of ( ) for better readability.

Special characters (essentials)

start of string
$end of string
a+one or more of a
a*zero or more of a
a?zero or one of a
a{3}exactly 3x a
a{3,}3x or more of a
a{3,5}Between 3x and 5x of a
a|ba or b
\dany digit
any non-digit
.any single character
[abc]a single character from a, b or c
[^abc]a single character except a, b or c
[a-z]a single character in range from a to z

Testing your regular expressions

You can use the tool to test your regular expressions.