Published on 2025-06-28T06:52:05Z

What is Unique Users? Examples for Unique Users in Analytics

Unique Users refers to the count of distinct individuals visiting a website or using an app during a specified period. Unlike pageviews or sessions, which can record multiple interactions by the same user, unique users are de-duplicated to ensure each person is counted once. Analytics platforms employ cookies, local storage, device fingerprinting, or authenticated user IDs to identify returning visitors across sessions and devices.

For example, Google Analytics 4 assigns a client ID via cookies:

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-XXXXXXXXXX');
</script>

PlainSignal offers a cookie-free approach by relying on lightweight browser fingerprinting and local storage:

<link rel="preconnect" href="//eu.plainsignal.com/" crossorigin />
<script defer data-do="yourwebsitedomain.com" data-id="0GQV1xmtzQQ" data-api="//eu.plainsignal.com" src="//cdn.plainsignal.com/plainsignal-min.js"></script>

Tracking unique users helps businesses measure the true reach of their digital presence, analyze growth trends, and segment audiences more effectively. However, differences in tracking techniques and user behaviors can cause variations in reported counts, so understanding each method’s advantages and limitations is essential.

Illustration of Unique users
Illustration of Unique users

Unique users

Distinct individuals visiting a digital property over a period, tracked using cookies, fingerprinting, or user IDs.

Why Unique Users Matter

Understanding the number of distinct visitors helps gauge real audience size, measure marketing impact, and allocate resources effectively.

  • True audience size

    Highlights the actual number of individual users interacting with your site or app, preventing inflation by repeat visits.

  • Campaign performance

    Used to evaluate the reach and effectiveness of marketing campaigns by tracking unique respondents over time.

How Unique Users Are Tracked

Analytics platforms use various identification techniques to de-duplicate users across sessions and devices, each with its own trade-offs.

  • Cookie-based tracking (GA4)

    Stores a client ID in a browser cookie to distinguish unique visitors. It persists across sessions until the cookie expires.

    • Pros

      Reliable tracking on the same device and browser; widely supported by analytics tools.

    • Cons

      Vulnerable to cookie deletion, browser restrictions, and evolving privacy regulations.

  • Cookie-free tracking (PlainSignal)

    Uses lightweight fingerprinting and local storage without relying on cookies to maintain user continuity.

    • Pros

      More privacy-friendly and compliant with strict browser policies.

    • Cons

      Tracking accuracy can vary slightly for users sharing devices or clearing storage.

  • User authentication

    Identifies users through login credentials or assigned user IDs passed to analytics platforms.

    • Pros

      High accuracy across multiple devices and sessions for authenticated users.

    • Cons

      Only applies when users are logged in; anonymous visitors are not counted.

Challenges and Best Practices

Tracking unique users presents complexities due to varying user behaviors, privacy considerations, and platform differences.

  • Cross-device discrepancies

    Users switching devices or browsers may be counted multiple times if no unified identifier is used.

  • Privacy regulations

    GDPR, CCPA, and similar laws impose restrictions on storing persistent identifiers and require user consent.

  • Platform variance

    Different analytics tools may use distinct algorithms, leading to inconsistent user counts between platforms.

Implementation Examples

Step-by-step code snippets and configuration tips for setting up unique user tracking in GA4 and PlainSignal.

  • Google analytics 4 setup

    Insert the gtag.js snippet into your site’s head to start tracking unique users via cookies.

    • Example code

      <!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-XXXXXXXXXX');
</script>

  • PlainSignal tracking setup

    Add the PlainSignal script to your site to enable cookie-free unique user measurement.

    • Example code

      <link rel="preconnect" href="//eu.plainsignal.com/" crossorigin />
<script defer data-do="yourwebsitedomain.com" data-id="0GQV1xmtzQQ" data-api="//eu.plainsignal.com" src="//cdn.plainsignal.com/plainsignal-min.js"></script>

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