> For the complete documentation index, see [llms.txt](https://docs.adpage.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.adpage.io/faq/marketing-optimization/what-is-ga4-reporting-identity-and-how-does-behavioral-modeling-work.md).

# What is GA4 reporting identity and how does behavioral modeling work?

How GA4 recognises users across devices and sessions, the difference between Blended, Observed and Device-based reporting identity, and when behavioral modeling switches on.

In Google Analytics 4 (GA4), **reporting identity** decides which methods GA4 uses, and in which order, to combine and de-duplicate events from the same user across devices, browsers and sessions into one user journey.

{% hint style="info" %}
Changing your reporting identity does not change the underlying raw data. It only changes how GA4 renders your reports and explorations.
{% endhint %}

## How GA4 recognises users

GA4 uses the following identity spaces to recognise users:

* **User ID** — a persistent ID that your website or app supplies, for example the account ID of a logged-in user. This is the most accurate cross-device identifier.
* **Device ID** — the client ID from the `_ga` cookie on websites, or the App Instance ID in mobile apps.
* **Modeled data** — machine-learning estimates of user activity and conversions when cookies or User IDs are not available, because of the visitor's consent choice or browser restrictions.

## Comparing the reporting identity options

You find this setting in GA4 under **Admin > Data display > Reporting identity**. There are three options:

| Reporting identity | Evaluation order                                     | What it means                                                                                                                                                                 |
| ------------------ | ---------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Blended**        | <p>1. User ID<br>2. Device ID<br>3. Modeled data</p> | The most complete option. Combines observed data with machine-learning modeled data to fill the gaps left by visitors who decline cookies.                                    |
| **Observed**       | <p>1. User ID<br>2. Device ID</p>                    | Uses only observed data from visitors who granted consent. No behavioral modeling.                                                                                            |
| **Device-based**   | 1. Device ID only                                    | Ignores User IDs and modeled data. Uses only the client or app ID, which can lead to higher user counts because the same person on several devices is counted more than once. |

## When does behavioral modeling switch on?

Selecting **Blended** enables behavioral modeling, but the modeling only becomes active once your property meets Google's traffic and technical requirements. Until then, GA4 shows the message: *"Modeling is unavailable for this property. Once it's available, it will be turned on by default in your reports."*

Your property must meet **all** of the following conditions:

1. **Advanced Consent Mode** — Google Consent Mode is active on all pages, so cookieless pings (`analytics_storage='denied'`) are still sent when visitors decline cookies.
2. **Enough consented users** — at least 1,000 daily users with `analytics_storage='granted'`, on at least 7 of the past 28 days.
3. **Enough unconsented events** — at least 1,000 daily events with `analytics_storage='denied'`, for at least 7 consecutive days.

{% hint style="warning" %}
Once these thresholds are reached, GA4 needs roughly 7 to 14 days to train and validate its models before modeled data appears in your reports.
{% endhint %}

## What changes in your reports with Blended identity?

Once modeling is active, Blended identity changes your GA4 numbers compared to Observed or Device-based:

* **Higher traffic counts** — Users, New users and Sessions go up, because GA4 now estimates the visitors who declined cookies and were previously left out.
* **Restored conversion totals** — key events (conversions) by visitors who declined cookies are estimated, so total conversions and conversion rates become more realistic.
* **Better marketing attribution** — modeled conversions are assigned to their likely channel (for example Organic Search, Paid Search or Social) instead of disappearing from channel reports.
* **More complete funnels** — gaps in path and funnel explorations are filled in, so it is easier to see where visitors drop off.
* **Less reporting bias** — your reports no longer lean towards the visitors who accept cookies, giving a more balanced dataset.

## Good to know

* **Non-destructive and retroactive** — switching between Blended, Observed and Device-based does not change your stored data. It only changes how reports calculate and display data, including historical data. You can switch back and forth freely.
* **BigQuery export contains observed data only** — the raw data GA4 exports to BigQuery contains only observed data. Modeled estimates from Blended reporting are not exported to BigQuery.


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