How to Merge Two Google Analytics Accounts

Trying to analyze your website performance when your data is spread across two different Google Analytics accounts can feel incredibly frustrating. While Google doesn't offer a magic "merge" button to combine historical data from two separate properties, you can absolutely centralize your reporting to get a complete, unified view of your traffic. This tutorial will walk you through practical methods for bringing your GA data together.

Graphed

Still Building Reports Manually?

Watch how growth teams are getting answers in seconds — not days.

Watch the Demo

Why You Can't "Actually" Merge Google Analytics Accounts

First, let's clear up a common misconception. You can’t literally fuse two GA properties into one. Google Analytics processes and stores data for each property in a permanent, isolated container. This is intentional and serves a few important purposes:

• Data Integrity: It prevents historical data from being accidentally corrupted or overwritten. Once data is processed and stored for a property, it’s locked in.
• Historical Accuracy: Merging could create conflicting or messy data. For example, what would happen to user counts or session data from two different domains if they were suddenly squashed together? The numbers wouldn't be reliable.
• Structural Separation: An "Account" is the highest level of organization, typically for a company. Under an account, you have "Properties" (a website or app), and under properties, you have "Data Streams" (the specific flow of data). This hierarchy is designed to keep data distinct.

So, the goal is not to force a technical merge. The goal is to set up a system where you can report on the data from both properties in a single place.

Your Two Paths to a Unified View

Since you can't rewrite history, you have two primary strategies depending on what you want to achieve. Each solves a different part of the problem.

1. The "Fresh Start" Approach: Track both of your websites under a single, new GA4 property from this day forward. This unifies all your future data collection.
2. The Centralized Dashboard Approach: Use a reporting tool like Looker Studio to pull data from both of your existing GA properties into one combined dashboard. This unifies your historical and future reporting.

For the best possible outcome, you can even use both methods together. We’ll show you how.

Method 1: Unify Future Tracking with a Single GA4 Property

This approach involves choosing one GA4 property as your "master" and sending data from both of your websites to it. It’s ideal if your main goal is to accurately track the user journey between your sites moving forward.

When to Use This Method:

• You have two closely related sites, like a main e-commerce store (mystore.com) and its blog on a separate domain (myblog.com).
• You've just acquired a new website and want to track its performance alongside your existing portfolio in one place.
• Having clean, perfectly integrated data from today onward is more important than blending historical records.

Graphed

Still Building Reports Manually?

Watch how growth teams are getting answers in seconds — not days.

Watch the Demo

Step-by-Step Instructions

1. Choose or Create Your Master Property

Decide which GA4 property will serve as the central hub. To avoid confusion, it's often best to create a brand new GA4 property specifically for this purpose. Let's call it "Master Website Tracking."

2. Find Your Measurement ID

In your new "Master" GA4 property, navigate to the Admin section (the gear icon at the bottom-left).

• Under the Property column, click on Data Streams.
• Select the web data stream.
• Your Measurement ID (starting with G-XXXXXXXXXX) will be in the top right. Copy this ID.

3. Update Your Second Website's Tracking

Now, go to the second website—the one whose data you want to send to the master property. You need to replace its current GA tracking code with the Measurement ID you just copied. The exact process depends on how you’ve installed Google Analytics.

• If using Google Tag Manager (Recommended): This is the easiest and most flexible way. In your GTM container for the second site, go to Tags and find your "Google Analytics: GA4 Configuration" tag. Simply replace the old Measurement ID with your new "Master" one. Publish the container, and you're good to go.
• If using a CMS Plugin (WordPress, Shopify): Go to your plugin's settings where you initially pasted the GA tracking ID. Replace the old one with the new master Measurement ID and save the changes.
• If hard-coded in HTML: You’ll need to work with a developer to find the gtag.js snippet in your website's code and update the G- ID there.

Once you’ve done this, both sites will be sending data to the same GA4 property.

4. Set Up Cross-Domain Tracking (Critically Important!)

Just sending data to the same property isn't enough. Without this next step, if a user clicks a link from your first site to your second, Google Analytics will see them as two separate visitors, breaking the user journey. Cross-domain tracking fixes this.

In your master GA4 property's Admin panel:

1. Go back to Data Streams and select your web stream.
2. Scroll down and click Configure tag settings.
3. Under the Settings section, click Configure your domains.
4. Click Add condition.
5. Enter the domains for both of your sites (e.g., yourcoolstore.com and yourcoolblog.com).
6. Click Save.

This tells GA that these two domains belong to you. Now, when a user clicks a link from one to the other, GA will automatically add a special _gl parameter to the URL. This parameter acts like a passport, telling GA it's the same person continuing their session, not a new visitor arriving from a "referral."

Pros and Cons of This Method

Pros:

• Provides a single source of truth for all future data.
• Enables true cross-domain user journey analysis within the GA4 interface.
• Simplifies reporting moving forward.

Cons:

• Does not merge your historical data. The old property for site #2 will still exist with all its past data, but it will be separate from your new master report.

Graphed

Still Building Reports Manually?

Watch how growth teams are getting answers in seconds — not days.

Watch the Demo

Method 2: Combine All Data in a Reporting Tool (like Looker Studio)

This is the best way to get a complete story by combining all your historical data from both properties with all of your new data. You'll use an external business intelligence tool to connect to both GA properties and build a unified dashboard.

When to Use This Method:

• Analyzing past trends across both websites is a high priority.
• You cannot or do not want to change the existing tracking setup on your sites.
• You want to build a master dashboard that blends GA data with other marketing tools (like Google Ads, HubSpot, or Salesforce data).

We'll use Google's own Looker Studio because it's free and integrates directly with Google Analytics.

Step-by-Step Looker Studio Guide

1. Create a New Report in Looker Studio

Go to https://lookerstudio.google.com/ and start a Blank Report.

2. Add Your First GA Property as a Data Source

Looker will immediately prompt you to add data. In the list of Google Connectors, find and select "Google Analytics." Authorize your account, and then select the first Account > Property > Data Stream you want to include. Click Add.

3. Add Your Second GA Property as Another Data Source

Your first property is now in the report. To add the second, go to the top menu and click Resource > Manage added data sources. Click the ADD A DATA SOURCE button and repeat the process from step 2, this time selecting your second Google Analytics property.

You now have two separate data sources loaded into one report. Now, we blend.

4. Blend Your Data for Combined Visuals

Data blending lets you combine information from multiple sources. Let's create a scorecard that shows total sessions from both websites.

1. Add a chart to your report, like a Scorecard.
2. When the scorecard is selected, look at the Setup panel on the right. Under Data source, you'll see your first GA property listed. Click on its name, and at the bottom of the pop-up, click BLEND DATA.
3. You’ll now see a new interface. Your first data source is on the left (Table 1). Click on "Join another table" and select your second GA property data source (Table 2).
4. Configure the Join: The most crucial step is telling Looker how to match up the rows from each table. For daily data, the Date dimension is perfect. Click on "Configure join", select the "Left outer" join type, and under Join conditions, select Date for both tables.
5. Add Your Metrics: In Table 1, add Sessions as a metric. Do the same for Table 2. Click Save.

5. Create a Calculated Field for the Total

Your blended data source is created, but Looker won't automatically add the sessions together. You need to tell it to.

1. With the scorecard still selected, hover over its metric in the Setup panel and click the little calculator icon to create a new Calculated Field.
2. Give it a name like "Total Sessions".
3. In the formula box, input:

SUM(Sessions) + SUM(Sessions (Table 2))

Note: The exact metric names might vary slightly based on your sources, just find the session/user metrics from both tables. 4. Click Apply.

Voilà! Your scorecard now proudly displays the combined total sessions from both of your Google Analytics properties. You can repeat this blending and calculation process for users, conversions, and revenue to build out a complete, unified dashboard reflecting your entire web presence.

Graphed

Still Building Reports Manually?

Watch how growth teams are getting answers in seconds — not days.

Watch the Demo

Pros and Cons of This Method

Pros:

• Combines both historical and future data into a single view.
• No changes needed for your website's tracking codes.
• Highly flexible for creating custom dashboards with other data sources.

Cons:

• Reporting lives outside of the native GA4 interface.
• Can’t show a true user journey across domains, it can only sum up the totals from each.
• Data blending can get complex, and there's a learning curve to Looker Studio.

Final Thoughts

Ultimately, unifying your Google Analytics data comes down to centralizing your reporting. You can either implement unified tracking for a clean slate moving forward (Method 1) or use a powerful tool like Looker Studio to blend your past and present data into a master dashboard (Method 2). For the ultimate solution, using both methods in tandem gives you accurate future tracking and complete historical context.

We know that even with tools like Looker Studio, the process of blending data, building formulas, and designing reports can become a significant drain on your time. We built Graphed to remove this friction entirely. Instead of configuring data sources and joins manually, you just connect your Google Analytics accounts in a few clicks. Then, you can ask in plain English, "Create a dashboard showing my combined sessions, users, and conversions from both my main site and my blog for the past six months," and Graphed builds the real-time, blended dashboard for you instantly.