What Is Google Analytics 4 - Collect?

Google Analytics 4, commonly referred to as GA4, is the latest iteration of Google's web analytics platform, designed to provide deeper insights into user behavior across websites and apps. It offers a more holistic approach to analytics by integrating data from various touchpoints, including websites, mobile apps, and other digital platforms. GA4 focuses on user-centric measurement, emphasizing the importance of understanding individual user journeys and interactions.

Product Type: Analytics

Integration Type: Starter Kit & ID Sync

Event Source Type: Web and Mobile Browser

Event Scope: Full-funnel Events

GA4 Measurement Protocol vs Collect Endpoint

MetaRouter has two integrations for GA4:

GA4 - Measurement (Recommended): Uses the Measurement Protocol for server-side tracking with structured JSON data
GA4 - Collect: Uses the Collect endpoint, mimicking browser-based gtag.js behavior

For more information about Google Analytics 4 - Measurement, please see here.

Aspect	GA4 Measurement (Recommended)	GA4 Collect
Endpoint	`https://www.google-analytics.com/mp/collect`	`https://google-analytics.com/g/collect`
Method	POST	GET
Data Format	JSON payload (structured)	URL parameters (flat)
Authentication	API_SECRET + MEASUREMENT_ID	MEASUREMENT_ID only
Product Data	Structured `items` array	Encoded strings (`pr1`, `pr2`, etc.)
Consent Support	Full (`ad_user_data`, `ad_personalization`)	Limited
Device Object	Full device information	Not available
Geolocation	`ip_override`, `user_location` (Oct 2024)	Native (`_uip`)
Batch Processing	Events array	Individual events
Debug Mode	Via validation endpoint	`ep.debug_mode=true`
Use Case	Server-side tracking, batch processing	Browser-like behavior, simple setup
Release Status	Mature (2022), actively enhanced	Newer (2024)

Choose GA4 Measurement (Recommended) for: Server-side integrations, structured e-commerce data, consent management, batch event processing, mobile apps

Choose GA4 Collect for: Simple setup without API secrets, debugging (URL-visible parameters), scenarios requiring browser-like behavior simulation

Capabilities

Browser-like event tracking via the GA4 Collect endpoint, mimicking gtag.js behavior.
Simple setup with no API secret required — only a MEASUREMENT_ID is needed.
Native geolocation support via _uip (user IP address).
Multi-property support by configuring multiple destination IDs to route events to multiple GA4 properties simultaneously.
URL-visible parameters for easy debugging and validation.

Considerations

GA4 Collect vs Measurement - GA4 Measurement is the recommended server-side integration — structured JSON payload, full consent parameter support, batch processing, and device/geolocation objects. GA4 Collect mimics browser-based gtag.js behavior with simpler setup (no API secret required) but limited feature support. Use Collect when you need browser-like behavior simulation, URL-visible parameters for debugging, or want to avoid managing an API secret.
Known Limitations - No user engagement reporting (engagement metrics may not be fully available in GA4 reporting), cross-network reporting may not be present in user and traffic acquisition reports, and product information uses encoded strings (pr1, pr2) rather than structured arrays.
No API Secret Required - Unlike GA4 Measurement, the Collect integration requires only a MEASUREMENT_ID. No API secret is needed, which simplifies setup but also means there is no server-side authentication on the request.
gclid and dclid Mapping - Unlike GA4 Measurement, the Collect integration maps gclid and dclid at the event level as URL parameters, reflecting the browser-like behavior of the Collect endpoint. Ensure the Google Gtag sync is configured so these values are available in context.providers.googleGtag.data.
Multi-Property Support via Destination IDs - Including multiple destination IDs in the Gtag sync instantiates separate gtag configs, routing events to multiple GA4 properties simultaneously. This is useful for multi-region setups or A/B testing across properties. Note that single-property support is the recommended default — only add multiple destinations if explicitly required.
Custom Dimensions for User Parameters - To surface user parameters (e.g., metarouter_anonymousid) in GA4 reporting, they must first be registered as custom dimensions in GA4: navigate to Admin > Data Display > Custom Definitions, create a new dimension with Scope: User, and set the User Property to match the parameter name.

Getting Started - From Your Google Analytics Account

Google Ads Auto-Tagging

Enable Google Ads auto-tagging for Google Ads reporting.

Auto-tagging automatically imports Google Ads data into Analytics. Combining Google Ads data with the rich post-click information provided by Analytics allows you to see what happened on your site after people clicked on your ads. When you enable auto-tagging, a parameter called gclid is added to your landing page URL when a user clicks over to your site from an ad.

Obtain Your Measurement ID

Log in to your Google Analytics account.
Navigate to the Admin section.
In the "Property settings" column, expand "Data collection and modification", click on "Data Streams."
Here, you'll find a list of data streams associated with the property.
Click on the data stream for which you want to find the measurement ID.
The measurement ID is displayed at the top of the page (e.g., G-XXXXX00000).

Adding a Google Analytics 4 - Collect Integration

Google Tag Sync (ID Sync Configuration)

To gather the cid, gclid (Google click ID), dclid (Display click ID), session ID, and session count, you must configure a Google Gtag sync. The sync configuration differs based on whether you're using the decoupled or coupled architecture.

Architecture	Description	Documentation
GA4 Sync - Decoupled	GA4 as a separate sync under parent Google Tag Settings	Gtag Decoupled: sync GA4
Google Tag Sync - Coupled (Legacy)	GA4 bundled with CM360/Google Ads in single Google Gtag sync	Gtag Coupled: sync GA4

Both architectures use the same Google Gtag sync configuration and produce identical results. The sync configuration, parameters, and behavior described in the Google Tag Overview apply to both architectures.

Google Analytics 4 - Collect Starter Kit

From the integration library, add a Google Analytics 4 (Collect) integration. Then, fill out the Connection Parameters:

Connection Parameter	Description
`MEASUREMENT_ID`	The GA4 measurement ID is a unique identifier assigned to each Google Analytics 4 property, allowing data to be collected and associated with that specific property.

Destination IDs (Multi-Property Support)

Including multiple destination IDs in the array instantiates separate GTAG configs, allowing events to be routed to multiple GA4 properties. This is useful for:

Customers with multiple EU country-specific GTAGs
Multi-property setups (e.g., regional properties)
A/B testing across different GA4 properties

Example configuration:

["G-XXXXXXXXX", "G-YYYYYYYYY", "G-ZZZZZZZZZ"]

Add Integration to Pipeline

Once you've adjusted the starter kit:

Go to Pipelines > Select your Pipeline
Click the Right drop-down > Add Integration
Select your Google Analytics 4 - Collect integration and revision > Deploy

Event Mappings

MetaRouter provides all of the event mappings that Google integrations typically require. You may add custom events, parameters or mappings in accordance with Google Analytics 4 Event documentation.

Global Mappings

Global mappings apply to all events. If your parameter names don't match the Expected Inputs, overwrite them with your own.

Output Key	Description	Expected Input
`gclid`	String: Google Ad Click ID	Expression - Third segment extracted from GA click ID cookie value
`dclid`	String: Google Display Ads ID	Expression - Third segment extracted from Display click ID cookie value
`cid` Required	String: Client ID	Expression - Extracted from GA cookie (`_ga`), falls back to `anonymousId`
`dl`	String: Page URL (document location)	`context.page.url`
`dt`	String: Page title	`context.page.title`
`dr`	String: Page referrer	`context.page.referrer`
`ua` Highly Recommended	String: User agent (required for platform data)	`context.userAgent`
`_uip` Highly Recommended	String: User IP address (required for geolocation)	`context.ip`
`ci`	String: Campaign ID	`context.campaign.id`
`cs`	String: Campaign source	`context.campaign.source`
`cm`	String: Campaign medium	`context.campaign.medium`
`cn`	String: Campaign name	`context.campaign.name`
`cc`	String: Campaign content	`context.campaign.content`
`ck`	String: Campaign term	`context.campaign.term`
`sid` Highly Recommended	String: Session ID (required for session data)	`context.providers.googleGtag.data.sessionID`
`sct` Highly Recommended	Integer: Session count (required for session data)	`context.providers.googleGtag.data.sessionCount`
`_et` Required	Integer: Engagement time in milliseconds	`properties.engagement_time_milliseconds` (default: `1`)
`tid` Required	String: Tracking/Measurement ID	Enrichment - `MEASUREMENT_ID`
`v` Required	Integer: Protocol version (must equal 2)	Enrichment - `2`
`isDebugMode`	Boolean: Enable debug mode	Enrichment - `false` (set to `true` to enable; connection transform converts to `ep.debug_mode=true`)
`up.metarouter_anonymousid`	String: MetaRouter anonymous ID sent as user property	Expression - `anonymousId`

Note: To send a user parameter to GA4 (e.g., metarouter_anonymousid), you must first set up user parameters in GA4 as a custom dimension:

Navigate to Admin > Data Display > Custom Definitions in GA4
Click Create Custom Dimension
Name your dimension, set Scope to User, and set User Property to metarouter_anonymousid

Event Specific

Page

Output Key	Description	Expected Input
`en` Required	String: Event name	Enrichment - `page_view`
`isConversion`	Boolean: Mark as conversion	Enrichment - `true`

Pro

Output Key	Description	Expected Input
`ep-search_term`	String: Search term	`properties.query`
`en` Required	String: Event name	Enrichment - `search`

Product List Viewed

Output Key	Description	Expected Input
`ep-item_list_id`	String: List ID	`properties.list_id`
`ep-item_list_name`	String: List name	`properties.category`
`pr1`, `pr2`...	String: Product information (encoded)	Expression - Products array encoded as indexed key-value pairs
`en` Required	String: Event name	Enrichment - `view_item_list`

Product Clicked

Output Key	Description	Expected Input
`pr1`	String: Product information (encoded)	Expression - Single product encoded as key-value pairs
`en` Required	String: Event name	Enrichment - `select_item`

Product Viewed

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`epn-value`	Number: Monetary value	Expression - `properties.value`, falls back to `price × quantity`
`pr1`	String: Product information (encoded)	Expression - Single product encoded as key-value pairs
`en` Required	String: Event name	Enrichment - `view_item`

Product Added

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`epn-value`	Number: Monetary value	Expression - `properties.value`, falls back to `price × quantity`
`pr1`	String: Product information (encoded)	Expression - Single product encoded as key-value pairs
`isConversion`	Boolean: Mark as conversion	Enrichment - `true`
`en` Required	String: Event name	Enrichment - `add_to_cart`

Product Removed

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`epn-value`	Number: Monetary value	Expression - `properties.value`, falls back to `price × quantity`
`pr1`	String: Product information (encoded)	Expression - Single product encoded as key-value pairs
`en` Required	String: Event name	Enrichment - `remove_from_cart`

Cart Viewed

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`epn-value`	Number: Monetary value	Expression - Sum of `price × quantity` across all products
`pr1`, `pr2`...	String: Product information (encoded)	Expression - Products array encoded as indexed key-value pairs
`en` Required	String: Event name	Enrichment - `view_cart`

Checkout Started

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`ep-transaction_id`	String: Transaction ID	`properties.order_id`
`ep-coupon`	String: Coupon code	`properties.coupon`
`epn-value`	Number: Monetary value	Expression - Sum of `price × quantity` across all products
`epn-tax`	Number: Tax amount	`properties.tax`
`epn-shipping`	Number: Shipping cost	`properties.shipping`
`pr1`, `pr2`...	String: Product information (encoded)	Expression - Products array encoded as indexed key-value pairs
`en` Required	String: Event name	Enrichment - `begin_checkout`

Payment Info Entered

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`ep-coupon`	String: Coupon code	`properties.coupon`
`ep-payment_type`	String: Payment method	`properties.payment_method`
`epn-value`	Number: Monetary value	Expression - Sum of `price × quantity` across all products
`pr1`, `pr2`...	String: Product information (encoded)	Expression - Products array encoded as indexed key-value pairs
`en` Required	String: Event name	Enrichment - `add_payment_info`

Order Completed

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`ep-transaction_id`	String: Transaction ID	`properties.order_id`
`ep-coupon`	String: Coupon code	`properties.coupon`
`epn-value`	Number: Monetary value	Expression - Sum of `price × quantity` across all products
`epn-tax`	Number: Tax amount	`properties.tax`
`epn-shipping`	Number: Shipping cost	`properties.shipping`
`pr1`, `pr2`...	String: Product information (encoded)	Expression - Products array encoded as indexed key-value pairs
`isConversion`	Boolean: Mark as conversion	Enrichment - `true`
`en` Required	String: Event name	Enrichment - `purchase`

Order Refunded

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`ep-transaction_id`	String: Transaction ID	`properties.order_id`
`ep-coupon`	String: Coupon code	`properties.coupon`
`epn-value`	Number: Monetary value	Expression - Sum of `price × quantity` across all products
`epn-tax`	Number: Tax amount	`properties.tax`
`epn-shipping`	Number: Shipping cost	`properties.shipping`
`pr1`, `pr2`...	String: Product information (encoded)	Expression - Products array encoded as indexed key-value pairs
`en` Required	String: Event name	Enrichment - `refund`

Promotion Viewed

Output Key	Description	Expected Input
`ep-creative_name`	String: Creative name	`properties.creative`
`ep-creative_slot`	String: Creative slot	`properties.position`
`ep-promotion_id`	String: Promotion ID	`properties.promotion_id`
`ep-promotion_name`	String: Promotion name	`properties.name`
`en` Required	String: Event name	Enrichment - `view_promotion`

Promotion Clicked

Output Key	Description	Expected Input
`ep-creative_name`	String: Creative name	`properties.creative`
`ep-creative_slot`	String: Creative slot	`properties.position`
`ep-promotion_id`	String: Promotion ID	`properties.promotion_id`
`ep-promotion_name`	String: Promotion name	`properties.name`
`en` Required	String: Event name	Enrichment - `select_promotion`

Product Added to Wishlist

Output Key	Description	Expected Input
`cu`	String: Currency (ISO 4217)	`properties.currency` (default: `USD`)
`epn-value`	Number: Monetary value	Expression - `properties.value`, falls back to `price × quantity`
`pr1`	String: Product information (encoded)	Expression - Single product encoded as key-value pairs
`en` Required	String: Event name	Enrichment - `add_to_wishlist`

Required & Recommended Identifiers

These identifiers must be mapped to Google Analytics 4 - Collect for successful user matching. Without these IDs, events sent to GA4 may not appear in your dashboard. Required and recommended IDs are mapped as Global parameters to ensure they are added to every event.

Attribute	Description	Example	Sync Injector Required?
`cid` Required	Client ID	`35009a79-1a05-49d7-b876-2b884d0f825b`	Yes
`ua` Highly Recommended	User agent (for platform data)	`Opera/9.80 (Windows NT 6.0)...`	No
`_uip` Highly Recommended	User IP (for geolocation)	`1.2.3.4`	No
`sid` Highly Recommended	Session ID (for session data)	`AJKDLSJFKLJ2390SKDFJLKJ23KJF9`	Yes
`sct` Highly Recommended	Session count (for session data)	`620`	Yes

Additional Identifiers

These identifiers should be mapped whenever possible to ensure highest user match rates:

Attribute	Description	Example
`gclid`	Google Click Identifier (Google Ads, Search Ads 360)	`CjwKCAjwt-OwBhBnEiwAgwzrUkyN...`
`dclid`	Display Click Identifier (DV360 conversions)	`CKDdz-fE_IUDFYtTCQkdbyMOPg`

Additional Google Analytics 4 - Collect Documentation