About regular expressions (regex)

Google Analytics supports regular expressions, also known as "regex", so you can create more flexible definitions for things like data filters, key events, segments, audiences, content groups, and custom channel groups.

In the context of Google Analytics, regular expressions are specific sequences of characters that broadly or narrowly match patterns in your Analytics data.

For example, if you wanted to create a view filter to exclude site data generated by your own employees, you could use a regular expression to exclude any data from the entire range of IP addresses that serve your employees. Let’s say those IP addresses range from 198.51.100.1 - 198.51.100.25. Rather than enter 25 different IP addresses, you could create a regular expression like 198\.51\.100\.\d* that matches the entire range of addresses.

Or if you wanted to create a view filter that included only campaign data from two different cities, you could create a regular expression like San Francisco|New York (San Francisco or New York).

Note: By default, Google Analytics Regex is full regex and case sensitive. Partial regex requires the user to add metacharacters.

Regex metacharacters

Wildcards

. Matches any single character (letter, number or symbol) 1. matches
10, 1A

1.1 matches
111, 1A1

Examples

? Matches the preceding character 0 or 1 times 10? matches
1, 10

Examples

+ Matches the preceding character 1 or more times 10+ matches
10, 100

Examples

* Matches the preceding character 0 or more times 1* matches
1, 10

Examples

| Creates an OR match

Do not use at the end of an expression 1|10 matches
1, 10

Examples

Anchors

^ Matches the adjacent characters at the beginning of a string ^10 matches
10, 100, 10x

^10 does not match
110, 110x

Examples

$ Matches the adjacent characters at the end of a string 10$ matches
110, 1010

10$ does not match
100, 10x

Examples

Groups

( ) Matches the enclosed characters in exact order anywhere in a string

Also used to group other expressions (10) matches
10, 101, 1011

([0-9]|[a-z]) matches
any number or lower-case letter

Examples

[ ] Matches the enclosed characters in any order anywhere in a string [10] matches
012, 120, 210

Examples

- Creates a range of characters within brackets to match anywhere in a string [0-9] matches any number 0 through 9

Examples

Escape

\ Indicates that the adjacent character should be interpreted literally rather than as a regex metacharacter \. indicates that the adjacent dot should be interpreted as a period or decimal rather than as a wildcard.

216\.239\.32\.34 matches
216.239.32.34

Examples

Tips

Use simple expressions

Keeping your regular expressions simple makes it easier for another user to interpret and modify.

Match metacharacters

Use the backslash (\) to escape regex metacharacters when you need those characters to be interpreted literally. For example, if you use a dot as the decimal separator in an IP address, escape it with a backslash (\.) so that it isn’t interpreted as a wildcard.

Full regex vs partial regex

Google Analytics supports full regex by default. This means that, without adding metacharacters, the expression only returns exactly matching values. To create a partial regex and filter for dimensions containing a specific value, you can use metacharacters like ".*".

Example

Default full regex: City matches regex "San Francisco" will return only "San Francisco".
Partial regex: City matches regex ".*San Francisco.*" will return both "San Francisco" and "South San Francisco".

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