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Adobe Analytics and GA4 numbers don't match because the two tools do not share a unit of measure. Visits, sessions, visitors, users, page views, and views look like matching pairs in the interface, but each one follows its own rules. A migration or a parallel run exposes all of those rules at once.
Why the counts differ
Adobe reports Visits, Unique Visitors, Page Views, and Occurrences. GA4 reports Sessions, Users, Views, and Event count. The names look close enough to compare directly, but the definitions behind them are not the same. The default "Users" metric in most GA4 reports is Active users, which is a different count from a visitor count in Adobe.
| Adobe term | GA4 nearest equivalent | Why counts differ |
|---|---|---|
| Visits | Sessions | Both close on inactivity, but each tool has its own timeout setting and its own rules for when a new visit or session starts. |
| Unique Visitors | Active users | Adobe keys on the ECID; GA4 keys on a client_id per browser, plus an optional user_id. Cookie lifetimes and browser limits differ. |
| Page Views | Views (page_view and screen events) | Depends on which tags fire, when they fire, and how single-page app route changes are tracked in each setup. |
| Occurrences | Event count | Adobe builds counts from server calls; GA4 counts individual events in an event model, so one interaction can register differently. |
| Conversions by channel | Key events by source or medium | Attribution models and channel rules assign the same conversion to different sources, so the channel split changes. |
Identity: ECID cookies and GA4 client IDs
Adobe identifies a visitor with an Experience Cloud ID (ECID) issued through its identity service. GA4 identifies a browser with a client_id, and can add a user_id you send yourself plus Google signals when those are enabled. Each identifier lives in its own cookie with its own lifetime. Safari's tracking prevention limits how long script-set cookies last, so the result depends on whether the ID is set first-party on the server or by JavaScript in the browser. Two tools can see the same person and still count them as different visitors.
Visit and session timeouts
Both tools commonly default to 30 minutes of inactivity, but both timeouts are configurable. Adobe sets the visit timeout in report suite or virtual report suite settings. GA4 sets it in the session timeout settings for the property. Check both settings before comparing visit and session totals, because a change made in one tool and not the other will move the counts even when the traffic is identical.
Bot filtering and internal traffic
Adobe applies IAB bot filtering and custom bot rules configured per report suite. GA4 automatically excludes known bots and does not let you see or configure that list. Check the current documentation in each platform for the details, since the exact rules are not something to assume. Internal traffic filters are also set separately. A filter in one tool does not change the other, so office IP ranges, staging hostnames, and test traffic can be excluded in one place and counted in the other.
Attribution and channel rules
Adobe eVars have allocation settings, most recent or original, and expiration settings. Marketing Channels use processing rules that each company defines for itself. Attribution in Analysis Workspace (formerly Attribution IQ) offers many attribution models to compare. GA4 key events use the property's reporting attribution model, which can be data-driven or paid and organic last click, while acquisition dimensions such as first user and session source use rule-based logic. Conversions by channel will therefore differ by design, not because one tool is broken.
Channel grouping adds another layer. GA4 applies default channel group rules, and custom channel groups are possible. Adobe channel rules are custom per company. The same click can land in one channel in Adobe and a different channel in GA4, which makes a channel-level comparison look worse than the underlying traffic actually is.
Data processing and timing
GA4 can apply thresholding when Google signals is on, and sampling can appear in Explorations. Adobe Workspace data is generally unsampled, but virtual report suites and segments change what a report shows, so a report can look different from the raw data it is built on. GA4 data can take a day or more to finalize, which means a report pulled the same morning will not match one pulled a week later. Confirm the reporting time zone in each tool as well, because a shifted day will look like a data problem.
Implementation drift
Different tags fire on different pages and events. Adobe typically runs through Adobe Experience Platform Tags (formerly Launch), while GA4 typically runs through Google Tag Manager or gtag. Consent banners may gate the two differently, and a single-page app can have route changes tracked by one setup and missed by the other. GA4 is event-based, while Adobe uses server calls, such as s.t() for page views and s.tl() for link tracking. The same user action can therefore be one thing in Adobe and several things in GA4.
A reconciliation method that finds the real gap
Start small. A mismatch across a full quarter hides every cause at once. Work through one day and one page or event, export raw counts from both tools without changing anything, and only then start removing differences one at a time:
- Pick one day, one page, and one event that both tools track, and export the raw counts from each.
- Align the date range and reporting time zone in both tools before comparing a single number.
- Align filters for internal traffic, bots, test hostnames, and any virtual report suite or segment.
- Compare the visit or session timeout and the bot rules in both tools side by side.
- Only after those match, compare unit definitions: visits to sessions, visitors to users, page views to views.
- Write down the remaining gap and its cause for each part, not a single percentage.
Where Adobe should win
Adobe should stay the reference where the team has a long-standing, carefully governed configuration. That includes custom Marketing Channel processing rules, eVar allocation and expiration choices, and virtual report suites that have been used in executive reporting for years. Workspace is also the stronger place to compare several attribution models side by side. When historical comparability matters more than the new platform, keep Adobe as the source for those reports and document the change.
Where GA4 should win
GA4 should be the reference for event-level behavior in the new implementation, especially where the team is rebuilding tracking around events and wants one model across web and app. It is also the natural baseline for Google Ads reporting and for the default channel groups most new reports will use. The risk is treating GA4 default channel groups or default attribution as a neutral truth. They are a set of defined rules, and they should be written down in the same way Adobe rules are.
Go further with the platform mismatch guide, the web and app analytics mismatch guide, and the attribution models explainer. If you are running both tools in parallel and need a clear reconciliation plan, see our digital analytics services, or book a tracking audit: bring the disputed report and we’ll map the first workflow you can trust.
Frequently asked questions
Why does Adobe Analytics show different visit totals than GA4 sessions?
Visits and sessions are different counts. Each tool closes a visit or session on its own inactivity timeout, identifies visitors with its own IDs, and filters bots with its own rules. The totals can differ in either direction, so check the timeout and filter settings in both tools before deciding either one is wrong.
Should Adobe Analytics or GA4 be the source of truth during a migration?
Pick the source of truth per metric and per report, not for the whole account. Use the tool whose definition matches the question being asked, and write down the mapping so the team can explain each remaining gap during the parallel run.
How big a gap between Adobe Analytics and GA4 is normal?
There is no universal acceptable gap. Reconcile one day and one page or event with aligned time zones, filters, and bot rules first. Whatever gap remains after that should be explained line by line, not accepted because the totals look close.
Can MetricMaven help reconcile Adobe Analytics and GA4?
Yes. We map the Adobe and GA4 definitions, align timeouts, bot and internal traffic rules, time zones, and attribution settings so the team can explain what changed and why before a migration decision is made.