Why do I see different numbers in Fullstory and a third-party tool?

When comparing Fullstory to other analytics tools like Google Analytics or Adobe Analytics, it's common to see a 5-15% difference in sessions, visits, or visitors due to nuances in how each system captures and defines its data.

This article explains:

Common reasons for data discrepancies

Session, page view, and user counts are often calculated differently across tools. Different data capture or display settings can also impact your reports. This table provides common reasons for data discrepancies and tips for troubleshooting.

Cause of discrepancy Tips for troubleshooting
API Errors
Sometimes not all event data can be processed by Fullstory due to rate limits or cardinality limits being reached. 
Check under Settings > Integrations > API Errors to see if these type of errors are impacting your account.
Are both tools displaying data in the same timezone?
Fullstory's UI displays data using your browser's timezone.
Domain Capture
Are both tools capturing the same domains, URLs, and pages?

Check your Fullstory data capture settings under Capture data by domain to see excluded domains.

You can also use a dimensionality card like this and group by URL Host to quickly see all domains you capture today.

Geographic Restrictions
Are both tools capturing from the same regions or countries?
Check your Fullstory data capture settings under Capture data by location.
IP Blocking
Are both tools blocking the same IP addresses?
Check your Fullstory data capture settings under Block IP addresses.
Bot Exclusion
Are both tools excluding the same bots, spiders, and user-agents?
Check your Fullstory data capture settings under Block user-agents.


If you're comparing Fullstory to Google Analytics, note that Fullstory captures activity from Googlebot that Google Analytics ignores.

Session Timeout
Do both tools end sessions after the same period of inactivity?
Fullstory ends sessions after 30 minutes of inactivity.
Sampling for Data Capture or Reporting
If you are sampling, are you sampling the same way in both tools?
We anticipate differences across tools if you're using custom code to sample data capture.

Sampling may also be applied to reports when working with large data sets in tools like Google Analytics Universal, Google Analytics 4, or Adobe Analytics.
Position of the Fullstory snippet
How are your tracking snippets deployed?
If your Fullstory snippet is added further down in your code, it may take a bit longer to capture data. This could impact session duration data across tools.
Browser Support
Do both tools support the same browsers?
Fullstory supports these browsers.
Other Issues
What unique circumstances affect each tool?
Some Chrome extensions or AdBlockers may impact data capture differently across tools.


Troubleshooting discrepancies between Google Analytics and Adobe Analytics

Most discrepancies between Fullstory and Google Analytics or Adobe Analytics are caused by differences in how each system defines sessions, page views, active users, and more. It's common to see a 5-15% difference in sessions, visits, or visitors between Fullstory and other third-party analytics tools due to nuances in how systems capture and define data.

Find more detailed information about these tools in the sections below:

Discrepancies between Fullstory and Google Analytics


  • By default, sessions in Fullstory and Google Analytics end after 30 minutes of inactivity; however, you can adjust the session timeout in Google Analytics. If your session timeout settings change in Google Analytics, you can expect discrepancies with Fullstory.
  • If the campaign source changes mid-session, Google Analytics Universal (GAU) splits sessions into two. For example, if a user lands on a page via Campaign A, leaves the page, and comes back to it via Campaign B, GAU splits this into two sessions. Fullstory and Google Analytics 4 (GA4) do not.
  • GAU splits sessions into two at midnight based on the Google Property timezone. For example, if a user starts browsing at 11:55 p.m. and ends at 12:05 p.m., GAU splits this into two sessions. Fullstory and GA4 do not.

Page Views

  • GAU defines pageviews and unique pageviews differently. You can read more about those nuances here. GA4 does not differentiate between these two events.
  • In GA4, a pageview event occurs when a user loads a page of your website or when the active page changes their browser history state. This includes page refreshes. You can also manually send pageview events to GA4.
  • In Fullstory, a Visited Page event in a web session occurs whenever the domain or path changes in a navigate event or when an end event is received. This includes page refreshes.

Active Users

  • Per GAU, sessions are not incremented in cases where a session only consists of non-interaction events. This means that a user must interact with the content of the page. If there are no interaction events in a session, the session won't count toward the session count in GAU.
  • Conversely, Fullstory captures sessions if the user clicks or moves their mouse, scrolls, touches their mobile app screen and navigates to different pages (including navigation within a single-page app).
  • GA4 creates an active user if a user has an engaged session or when Analytics collects:
  • In GA4, active users appear as "Users" in reports. So, users who visit your site and do not capture an engaged session won't count toward this metric. Fullstory does not differentiate between Engaged Sessions and Low Engagement Sessions, so users with either type of activity are considered active, and a session will be captured.
  • GA4 excludes users with sessions less than 10 seconds from their unique user count. Fullstory does not.
Discrepancies between Fullstory and Adobe Analytics

Sessions vs. Visits

Adobe differentiates between sessions and visits – sessions end when the browser is closed, but visits end according to the timeout criteria above. Fullstory sessions are most comparable to Adobe Analytics visits.

  • In Fullstory, a session starts when the user first visits your site and ends after 30 minutes of inactivity, 24 hours of activity, if a mobile app is terminated (via swipe up or a full close), or if a device runs out of memory.
  • In Adobe Analytics, a visit starts when the user arrives on your site and ends after 30 minutes of inactivity, 12 hours of activity, more than 2,500 hits, or more than 100 hits in the first 100 seconds (suspected bot activity).
  • Customers using Virtual Report Suites can extend the 30-minute inactivity limit, and customers using Standard Report Suites can reduce it.
  • In Adobe, a new visit starts if the visitor:
    • Clears their cache mid-session and continues browsing your site.
    • Leave your site open in a tab for over 30 minutes, then continue browsing.
    • Opens a different browser and navigates to your site on the same computer.
    • The same person is browsing your site on other devices.
  • Adobe will not trigger a new visit (as long as the user is under the inactivity threshold) when the visitor:
    • Closes their browser, then navigates to your site again.
    • Restarts their computer, opens the same browser, and navigates to your site again.
    • Transitions to a different network, such as disconnecting from a wired network docking station to a wireless network.
    • Browses your site in multiple tabs. If a visitor switches back and forth between tabs, each hit counts as part of the same visit.
  • In Adobe, visits that span midnight attribute a visit to the starting and ending day; however, the total visit metric is deduplicated and shows a single visit for the given date range.

Users vs. Visitors

Users in Fullstory and visitors in Adobe Analytics often have different definitions. Here are the types of users and visitors you may come across and information on how they differ.

In Fullstory

  • Anonymous Users: Fullstory aggregates sessions from the same browser into a single Anonymous User via cookies.
  • Identified Users: Fullstory maintains user identity using cookies, which can change over time across devices. Using fs.identify, you can associate the current cookie with users as your application uniquely knows them. We use the term uid to refer to your app's ID for any given user.
  • Signed-Up Users: Signed-up users are users who have a uid, and anonymous users do not.

In Adobe Analytics

  • Visitors: Visitors often refer to users, but can sometimes refer to devices.
  • Unique Visitors: The number of unique visitor IDs. Multiple mechanisms exist to identify users, including cookies, IP addresses, and user agents.
  • Unique Devices: The number of unique unidentified devices, meaning devices that generate anonymous hits and unique virtual devices (distinct people identified per device).
  • People: The sum of individuals who are identified in the report, plus the number of devices that are not identified as belonging to a person.
  • Unidentified People: The number of visitors that Cross-Device Analytics (CDA) could not identify.
  • Identified People: The number of visitors that CDA could identify.

Pageviews (hits)

  • In Adobe Analytics, page views count the number of times a page is viewed based on the count of page view tracking calls (t()), and excludes link tracking calls (tl()). Page events are the opposite–the count link tracking calls but not page view tracking calls.
  • In Adobe Analytics, duplicated server calls (s.t()) for page visits can result in inflated page view metrics that affect many reports and other derived metrics. These issues are especially present for single-page applications.
  • In Fullstory, a Visited Page event in a web session occurs whenever the domain or path changes in a navigate event or when an end event is received. This includes page refreshes.

Cross-Device Analytics (CDA)

  • Adobe Analytics report suites cannot map to more than one organization ID. Since CDA stitches devices within a given report suite, CDA cannot be used to stitch data across multiple organization IDs.
  • Stitched data follows a latency of 8 to 12 hours.
  • Historical data in the virtual report suite changes based on Adobe recognizing and stitching devices together. Data in the source report suite does not change.
  • If using CDA, the Unique Visitors metric is replaced with the Unique devices metric.


When to reach out to Fullstory Support

If you see more than a 15% difference in session, user, or page view counts after looking over the information above, you can contact Fullstory Support for help investigating the discrepancy.

Note: If you have configured custom sampling of Fullstory sessions, we cannot troubleshoot unless you are sampling the exact same user activity in your third-party application. If you are unsure, we suggest contacting an internal technical resource at your organization.

Please include the following details for a single day of data:

  • The name of the tool you're comparing to Fullstory (i.e., Google Analytics 4, Universal Analytics, Adobe Analytics).
  • Confirmation that your data capture settings are the same in both systems, including the domains and URLs where capture is deployed, IP and user-agents that are blocked, inactivity timeout settings, and any geographical restrictions.
  • A link to the segment or metric you're viewing in Fullstory.
  • A screenshot of the related report in the other tool, including the date and timezone used.

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