Unique visitors in Google Analytics is an invaluable tool for measuring, tracking and understanding a site’s audience.
The official Google Analytics definition of this Web metric is: “Unique Visitors is the number of unduplicated (counted only once) visitors to your website over the course of a specified time period.”
Tracking this number monthly is an industry standard for understanding if a site’s audience is increasing, decreasing or staying even.
How to Find the Number
In Analytics, click on Audience in the top left of the page and then on Overview.
The graph at the top will show visits (not unique visitors) over the last 30 days. Visits is the number of times unique visitors come to a site.
For example, if the site has 10,000 unique visitors and 20,000 visits, it means that on average the unique visitors visited the site twice a month.
The unique visitor number is found below the graph in the list between Visits and Page Views.
Click on Unique Visitors to see its graph appear at the top of the page in place of the Visits graph.
What the Number Really Means
I have often thought that Google displays the Visit chart first because it thinks visits are more important than unique visitors.
One possible reason is that the unique visitor number is not always what it appears to be.
The number is calculated by using browser cookies.
It is not surprising that Google seems to place more importance on visits than unique visitors.
That said, the unique visitor number is an industry metric and does provide a useful way of tracking site audience.
Just use it carefully, work to increase the total and understand its limitations.