Does Google Optimize Work with Google Analytics 4?

If you're looking around for how to link Google Optimize with your new Google Analytics 4 property, you've probably hit a dead end. This article gives you the direct answer and, more importantly, lays out your path forward for running A/B tests. We'll cover what happened to Optimize, what your new options are, and how to analyze experiment results using GA4 and other modern tools.

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The Direct Answer: Google Optimize is No More

Let's get straight to it: Google Optimize was officially discontinued (or "sunsetted") on September 30, 2023. As of that date, all experiments and personalizations stopped running, and the tool is no longer accessible. So, no, Google Optimize does not work with Google Analytics 4, Universal Analytics, or anything else. It's simply gone.

For years, Optimize was the go-to free tool for many marketers and small businesses dipping their toes into conversion rate optimization (CRO). Its native integration with Universal Analytics made it an easy choice for running simple A/B tests, like checking one headline against another or testing a new call-to-action button color. But as the digital analytics landscape shifted towards the more powerful, event-based model of GA4, Optimize started to show its limitations.

The writing was on the wall for a while. The tool hadn't seen significant feature updates, and it lacked the raw power and flexibility of paid competitors. This ultimately led to Google's decision to shut it down and rethink how A/B testing fits into their ecosystem.

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Why Did Google Shut Down Optimize?

In their official announcement, Google stated that Optimize "does not have many of the features and services that our customers request and need for experimentation testing." This is a diplomatic way of saying that the tool was falling behind, and they would have needed to invest heavily to bring it up to par with industry leaders.

Building and maintaining a best-in-class experimentation platform is a massive undertaking. Instead of competing directly, Google made a strategic shift: transform Google Analytics 4 from a simple measurement tool into a central hub for analyzing data from many sources, including sophisticated, third-party A/B testing platforms.

The idea is no longer to use a lightweight, built-in tool. Instead, Google is encouraging users to integrate powerful, specialized A/B testing tools directly with GA4. They even announced official integrations with leading platforms like Optimizely, VWO, and AB Tasty, signaling a clear path forward for marketers who rely on experimentation.

Your New Game Plan: A/B Testing with GA4 Integrations

While GA4 is not an A/B testing tool itself, it's designed to be the ultimate analysis engine for the data your testing tool collects. Connecting a dedicated experimentation platform to GA4 unlocks a much deeper level of insight than was ever possible with Google Optimize. Here’s why this new approach is a major upgrade:

• Comprehensive User Journeys: Your A/B testing tool tracks how users behave within an experiment. GA4 tracks the entire user journey across your website or app. Integrating them lets you see how a variation not only affects the conversion goal (like a click) but also impacts long-term behavior like user retention, average order value, and lifetime value.
• Powerful Audience Targeting: With GA4, you can create highly specific audiences based on behavior, demographics, or purchase history - for example, "users from the US who viewed 3+ product pages and abandoned their cart in the last 7 days." You can then push these audiences directly into your integrated A/B testing tool to run experiments targeted at very specific user segments.
• Flexible Success Metrics: Universal Analytics and Optimize were built around session-based goals. GA4’s event-based model lets you measure anything. You can define success for your experiments based on custom events that matter to your business, like ebook_download, demo_request_submitted, or added_premium_feature. This allows for a much more nuanced understanding of an experiment's true impact.

Top Alternatives That Integrate with Google Analytics 4

Since Google Optimize’s retirement, the market for A/B testing tools has heated up. Here are a few leading platforms that offer strong integrations with Google Analytics 4.

1. Optimizely

Often considered the enterprise-grade leader in digital experimentation, Optimizely offers a powerful suite of tools for A/B testing, multivariate testing, and server-side experimentation. Its partnership with Google makes its GA4 integration one of the most robust available. You can seamlessly share audience data between platforms and get incredibly detailed reports.

Best for: Large enterprises and mature marketing teams with a dedicated budget for CRO.

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2. VWO (Visual Website Optimizer)

VWO is another major player known for its user-friendly visual editor and comprehensive CRO toolkit, which includes not just A/B testing but also heatmaps, session recordings, and surveys. Its GA4 integration allows you to push VWO experiment data into GA4, so you can analyze a test’s impact on all of your standard metrics and custom events.

Best for: Mid-market businesses and SMBs looking for a powerful yet accessible A/B testing and CRO platform.

3. AB Tasty

Another official Google Cloud partner, AB Tasty is a strong contender that focuses on providing an all-in-one platform for experimentation, personalization, and feature management. Its bidirectional integration with GA4 is a key feature, enabling you to use GA4 audiences for targeting in AB Tasty and to view experiment results within the context of your broader business data in GA4.

Best for: Businesses of all sizes that want to run both marketing and product experiments from a single platform.

4. Firebase A/B Testing (For Apps)

This is an important distinction to make. Many people assume Firebase A/B Testing is the new Google Optimize, but it's designed exclusively for mobile apps (iOS and Android), not websites. If your primary goal is to optimize a mobile app experience, Firebase's integration with Google Analytics is deeply embedded and extremely powerful. It won’t, however, work for testing your website's landing page.

A Step-by-Step Guide to Connecting Your New Testing Tool to GA4

While the exact steps vary by platform, setting up the GA4 integration for most testing tools follows a similar pattern. Here's a general overview of what to expect:

1. Select Your Platform: Choose an experimentation tool like VWO, Optimizely, or AB Tasty that officially supports a GA4 integration. This ensures the connection is reliable and well-documented.
2. Install the Code Snippet: Just like with Optimize, you'll need to add a small JavaScript snippet from your new tool to the <head> section of your website's HTML. Most tools have plugins for popular platforms like WordPress or Shopify to make this easier.
3. Authorize the Connection within Your Tool: Log into your A/B testing platform's dashboard. Find the "Integrations" section and select Google Analytics 4. You'll be prompted to log in with your Google account and grant the platform permission to access your GA4 property data. This is typically done through a secure OAuth process.
4. Configure Data Sharing: Once connected, you’ll usually have options to control what data is sent. At a minimum, you'll want to enable the setting that sends experiment and variation data to GA4 as an event. You might also see options for importing GA4 audiences.
5. Verify the Integration is Working: After launching a test, go to your GA4 property and open the Realtime report or head to Admin > DebugView. Within moments of being included in an experiment, you should see events appear with names like vwo_experiment_viewed or experiment_impression. These events will have parameters attached, such as experiment_id and variant_id, confirming that data is flowing correctly.

How to Analyze A/B Test Results in GA4

Once data from your A/B tests is flowing into GA4, you can move beyond your testing tool’s built-in dashboard and analyze results alongside all of your other crucial business metrics.

Your experiment data is sent over as an event (e.g., experiment_impression) with parameters that identify the test and variation. For these parameters (like experiment_id and variant_id) to be usable in your reports, you first need to register them as custom dimensions in GA4 by going to Admin > Custom definitions > Custom dimensions.

After that's done, here are two ways to analyze your data:

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1. Using Comparisons in Standard Reports

This is a quick way to see how two variations stack up. In any standard report, like the Traffic acquisition report, you can add a Comparison.

• Create your baseline segment (Control):
• Create your second segment (Variant):

Now, the report will show metrics like user counts, engagement rates, and conversions side-by-side for the control and the variation, letting you quickly spot performance differences.

2. Building an Exploration Report

For more detailed analysis, head to the Explore section and build a Free-form report.

• Rows: Add your custom dimension for Variant ID.
• Values: Add the metrics you care about, like Sessions, Conversions, Total users, and Purchase revenue.
• Filters: Add a filter for Experiment ID and set it to match the ID of the experiment you want to analyze.

This will create a clean table showing a head-to-head performance breakdown for all your key metrics, giving you a full picture of your experiment's outcome.

Final Thoughts

While the retirement of Google Optimize marked the end of an era for free, simple A/B testing, it pushed the industry toward a much more powerful and integrated approach. By pairing a dedicated experimentation platform with Google Analytics 4, marketers can gain richer insights, run more targeted tests, and measure the true impact of their efforts on core business goals.

As you connect these platforms, keeping all your marketing and analytics data in one cohesive view can become a challenge. At Graphed, we plug directly into data sources like Google Analytics 4, your advertising platforms, and your CRM to simplify your reporting. Instead of digging through multiple platforms or building complex Exploration reports, you can just ask in plain English, "Compare traffic and conversions for my home page headline test this month," and get an instant visualization. We automate the data gathering so you can spend your time acting on insights, not looking for them.