Digital Marketing Academy · Lesson

GA4 vs Universal Analytics

The event-based shift.

GA4 vs Universal Analytics is a free Digital Marketing Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Digital Marketing Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Why GA4 Replaced UA

Universal Analytics (UA) stopped processing new data on July 1, 2023. Google Analytics 4 (GA4) is now the only supported version.

The shift was not a redesign. GA4 uses a completely different data model built for privacy, cross-device tracking, and a cookieless future.

Understanding the differences prevents wrong assumptions when reading reports you migrated from UA.

Sessions vs Events

UA was session-based. Everything rolled up into sessions, and hit types (pageview, event, transaction) were separate concepts.

GA4 is event-based. Every interaction is an event with parameters, including page_view itself. This unifies web and app data under one schema.

UA hit types:
  - pageview
  - event (category / action / label)
  - transaction
  - social

GA4 model:
  - everything is an event
  - page_view  -> event
  - purchase   -> event
  - scroll     -> event
  - parameters carry the detail

The Event Schema

In UA, events used a rigid Category / Action / Label / Value structure. It was hard to extend.

GA4 events have a name plus flexible parameters (up to 25 per event). This is far more expressive and maps cleanly to app analytics.

UA event:
  category: "Video"
  action:   "Play"
  label:    "Intro"
  value:    1

GA4 event:
  event_name: "video_start"
  parameters:
    video_title: "Intro"
    video_provider: "youtube"
    video_percent: 0

Automatic Measurement

GA4 collects many interactions out of the box via Enhanced Measurement. In UA most of these required manual tagging.

Toggle them in the data stream settings. This reduces setup time but you should know what is auto-tracked to avoid double counting.

Enhanced Measurement auto-events:
  - page_view
  - scroll (90% depth)
  - click (outbound links)
  - view_search_results
  - video_start / video_progress / video_complete
  - file_download
  - form_start / form_submit

Bounce Rate Is Gone

UA bounce rate = single-page sessions with no interaction. GA4 replaced it with Engagement Rate, the percentage of engaged sessions.

An engaged session lasts 10+ seconds, has a conversion, or includes 2+ page views. Bounce rate in GA4 is simply 1 minus engagement rate.

Engaged session = any of:
  - duration >= 10 seconds, OR
  - 1+ conversion event, OR
  - 2+ page_view / screen_view events

Engagement Rate = engaged_sessions / total_sessions
Bounce Rate (GA4) = 1 - Engagement Rate

Users and Identity

GA4 prioritizes user-centric reporting over sessions. It stitches identity across devices using Google signals, User-ID, and device data.

UA leaned heavily on cookies. GA4 blends machine learning modeling to fill gaps when cookies are missing, supporting privacy regulations.

GA4 identity spaces (priority order):
  1. User-ID (your logged-in ID)
  2. Google signals (signed-in Google users)
  3. Device ID (cookie / app instance)
  4. Modeling (behavioral, when consent denied)

Data Retention Limits

GA4 standard event-level data retention defaults to 2 months and can be extended to 14 months. Aggregated standard reports are kept longer.

For analysis beyond 14 months, export raw data to BigQuery, which GA4 offers free at the standard tier (a big change from UA).

Retention settings (Admin > Data Settings):
  Event data retention: 2 months (default)
                        14 months (max, standard)

Long-term solution:
  GA4 -> BigQuery export (free)
  query historical events with SQL

Conversions vs Goals

UA had Goals configured at the View level (destination, duration, pages, events). GA4 has no Views and no Goals.

Instead, you mark any event as a conversion. This is simpler but means you plan your event taxonomy first, then promote key events.

UA Goal types:
  - Destination (thank-you URL)
  - Duration
  - Pages/session
  - Event

GA4 conversion:
  Admin > Events > toggle
  "Mark as conversion" on event
  e.g. generate_lead, purchase, sign_up

No More Views

UA structure was Account > Property > View. Views let you create filtered copies of data.

GA4 is Account > Property > Data Stream. Filtering now happens with data filters, comparisons, and subproperties (360). This simplifies governance but changes how you isolate dev traffic.

UA:  Account > Property > View(s)
GA4: Account > Property > Data Stream(s)

Replace View filters with:
  - internal traffic data filter
  - developer traffic data filter
  - report-level comparisons

Reporting Interface

GA4 reports are leaner. The Reports section gives standard summaries; deep custom analysis lives in the Explore section.

UA users often miss prebuilt reports. In GA4 you customize the report library or build Explorations to recreate familiar views.

Where things moved:
  UA Behavior > Site Content -> Reports > Pages and screens
  UA Acquisition > Channels  -> Reports > Traffic acquisition
  UA Custom Reports          -> Explore (free-form, funnel, path)
  UA Audiences               -> Admin > Audiences

Migration Checklist

A clean migration is not a copy. Recreate your measurement plan around events and parameters from the start.

Confirm conversions, link Google Ads, set retention to 14 months, enable BigQuery export, and configure internal traffic filters before trusting the data.

Migration checklist:
  [ ] map UA goals -> GA4 conversion events
  [ ] enable Enhanced Measurement
  [ ] set data retention to 14 months
  [ ] define internal traffic filter
  [ ] re-link Google Ads & Search Console
  [ ] turn on BigQuery export
  [ ] validate in DebugView

Quick Check

Test your grasp of the core model difference.

Recap

GA4 replaced UA with an event-based, user-centric model. There are no Views or Goals, bounce rate became engagement rate, and identity blends User-ID, Google signals, and modeling.

Plan events first, mark key ones as conversions, extend retention, and use BigQuery for history. Migration means rebuilding, not copying.

Frequently asked questions

Is the “GA4 vs Universal Analytics” lesson free?

Yes — the full text of “GA4 vs Universal Analytics” is free to read here on the web, and the Digital Marketing Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Digital Marketing Academy course, upgrade to CoddyKit PRO.

What will I learn in “GA4 vs Universal Analytics”?

The event-based shift. You practise Digital Marketing Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Digital Marketing Academy?

No prior experience is required. Digital Marketing Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “GA4 vs Universal Analytics” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Digital Marketing Academy lesson?

Yes. Every Digital Marketing Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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