What Is UU? Meaning, Differences from Related Terms, and How to Use It

Have you ever wondered, "What exactly is 'UU' that I keep seeing in access analytics?" or "How is it different from PV or sessions?" UU (Unique Users) is one of the most fundamental metrics in web marketing, showing 'how many people' visited your website. This article explains everything from the meaning of UU to how it differs from related terms, how to check it in GA4, and concrete ways to increase it, in a way that is easy for beginners to understand.

What Is UU (Unique Users)?

UU stands for "Unique User," and it is a metric that shows the number of users (people) who visited a website within a given period, excluding duplicates. No matter how many times the same person visits the site within the same period, they are counted as "1" UU.

For example, even if the same user visits the same website five times in one week, because they are all the same person, the UU count is "1" rather than five. In this way, UU measures the "number of people who visited" rather than the "number of visits."

UU is an essential metric for measuring how many people see your site, in other words, its ability to attract visitors. Because it captures the pure number of users with duplicates removed, you can accurately evaluate the actual reach of your site.

UU is often confused with metrics such as PV, sessions, and active users. Correctly understanding the differences between them greatly improves the accuracy of your access analysis. Here we sort out the differences with three representative metrics.

UU vs. PV (Page Views)

PV (Page Views) represents the total number of times pages were viewed within a site. The decisive difference is that while UU counts the "number of people," PV counts the "number of user actions (page views)."

When the same user views multiple pages or opens the same page repeatedly, PV increases each time. UU, on the other hand, does not increase. For this reason, PV is usually a larger figure than UU.

By calculating PV divided by UU, you can find the "average number of pages viewed per person," which serves as a guide for evaluating how well users navigate around your site.

UU vs. Sessions

A session represents a series of actions (a visit) from when a user arrives at the site until they leave. Even for the same user, if they return after some time has passed, it is counted as a separate session.

In GA4, by default a session ends after 30 minutes of inactivity, and when the same user accesses the site again it is counted as a new session. In other words, one user (UU=1) can generate multiple sessions. By comparing UU with the number of sessions, you can understand how often visitors return to your site.

UU vs. Active Users (AU)

Active Users (AU) refers to the number of users who actually used a site or app within a given period. In GA4, UU (Unique Users) and Active Users are treated as essentially the same concept.

In GA4, the metrics "Total Users" and "Active Users" correspond to UU. Total Users is the total number of all users who accessed the site during the period, while Active Users is the number of those users who had engagement (specific actions). In practice, you can regard the Active Users figure displayed in GA4 as your UU count without any problem.

How UU Is Counted

UU is measured by access analysis tools such as Google Analytics. To identify and count users, the following three types of data are mainly used.

IP address: An identification number assigned individually to each device, such as a PC or smartphone. Visits from the same IP address are counted as UU=1 regardless of the number of visits.
Cookie: Identification information stored in the browser. It allows the tool to recognize the same user on a return visit.
Host name: Individual device data expressed in alphanumeric characters. The tool analyzes this to identify the visiting device.

However, if the same person uses multiple devices (such as a smartphone and a PC) or different browsers, they may be counted as separate users. For this reason, note that the UU count does not perfectly match the strict "actual number of people." Combining it with a mechanism that can identify users, such as membership registration, enables more accurate analysis.

How to Check UU in GA4

In the current Google Analytics 4 (GA4), UU is displayed as "Total Users" or "Active Users." There are mainly three ways to check it.

Home screen: On the home screen after logging in, you can immediately see the approximate number of Active Users and Total Users for the entire site.
Standard reports: From "Reports" in the left menu and then "Reports snapshot," you can check the number of Active Users accurately down to the ones digit.
Exploration reports: Use these when you want to perform more detailed and advanced analysis by combining UU with other metrics.

Use the home screen for a rough overview, standard reports when you need accurate figures, and exploration reports when you want deeper analysis, choosing the method according to your purpose.

Benefits of Using UU

Correctly measuring and analyzing UU offers the following benefits.

You can grasp pure attraction power: Because you know the number of people excluding duplicates, you can accurately evaluate how many people your site actually reaches.
You can measure the effectiveness of initiatives: By comparing UU before and after initiatives such as ads, social media posts, and email newsletters, you can objectively judge the effect of your acquisition efforts.
You can perform deeper analysis by combining metrics: Such as measuring navigation with PV/UU and return rate with sessions/UU, enabling multifaceted analysis.
You can measure the foundation for conversions: As UU increases, the pool of prospective users likely to lead to conversions such as inquiries and applications also tends to grow.

How to Increase UU (Unique Users)

To increase UU, the basics are to broaden the inflow channels for bringing new visitors to your site and to improve the quality of your content. There is no magical way to increase it easily in a short period; steady, accumulated improvement is what matters.

1. Diversify Your Inflow Channels

Rather than relying solely on organic search (SEO) or ads, prepare multiple inflow channels such as social media like X (formerly Twitter) and Instagram, email newsletters, and events such as seminars and exhibitions. Increasing your channels lets you acquire new users that search and ads alone could not reach.

2. Strengthen Content with SEO

Creating high-quality content that meets users' search intent and increasing organic inflow from search engines directly contributes to growing UU. Since users do not view content they do not need, continuously providing valuable information for readers is what matters most.

3. Make Use of Advertising

By utilizing listing ads, social media ads, and the like, you can increase the inflow of new users in a short period. By clarifying your target and preparing compelling creatives, you can grow UU efficiently.

Summary

UU (Unique Users) is an essential metric for measuring attraction power, representing the number of users who visited a website within a given period with duplicates removed. Keep in mind that PV counts "the number of views," sessions count "the number of visits," and UU counts "the number of visitors," each with a different counting target. In GA4, you can check UU as Total Users and Active Users. By diversifying your inflow channels and making use of SEO and advertising, steadily increase your UU and aim for effective website operation that leads to conversions.

What Is UU? A Thorough Explanation of Its Meaning, Differences from Related Terms, and How to Use It