Segment Overlap Report

January 6, 2026
  • First Published: January 6, 2026
  • Last Modified: January 6, 2026

Here’s a familiar frustration: you know you have users on mobile, and you know you have users aged 25-34, but figuring out exactly how those two groups interact and where they overlap with your high-value purchasers can feel like a headache.

Data often feels siloed in standard reports. You see one dimension or the other, but rarely the intersection.

Enter the Segment Overlap exploration in Google Analytics 4.

It’s essentially a dynamic Venn diagram tool that lets you visualise up to three segments at once.

It’s not just about pretty charts, though; it’s about isolating specific, complex audiences and taking action on them immediately.

If you want to move beyond basic reporting and start building retargeting lists based on actual user behaviour, this is where you start.

Table of Contents

Key Takeaways

  • Visualise Intersections: Compare up to three user segments to see where they overlap.
  • Instant Action: Right-click on any overlapping section to instantly create a new audience segment.
  • Isolate Complex Data: Filter by specific dimensions (like device, age, or traffic source) to find your “sweet spot” users.
  • Shareable Insights: Easily share read-only reports with stakeholders to back up your strategy.

Setting up a segment overlap report

The Segment Overlap report lives within the ‘Explore’ section of GA4. Its primary job is to show you the relationship between different groups of users.

Think of it as a way to validate your hunches. You might suspect that mobile users from London convert at a higher rate than desktop users from Manchester. This report confirms that overlap visually.

Setting It Up

Getting this running is straightforward:

  1. Head to the Explore section in the left-hand menu.
  2. You can start with a blank report and select the ‘Segment Overlap’ technique, or simply click the Segment Overlap template
  3. Configure your segments: You can drag and drop up to three segments into the comparison block.
  4. Add Breakdowns: Want more detail? Drag a dimension (like ‘Country’ or ‘Session Source’) into the breakdown row to see the data split further in the table below the chart.

Note: You can limit the number of rows displayed or filter the data to keep things tidy. This is helpful if you’re analysing high-traffic sites and need to cut through the noise.

Segment Overlap

Using the segment overlap report

Once you have your segments loaded, the visualisation isn’t just a static image; it is an interactive tool designed to help you isolate specific groups of users.

Here is how you can manipulate the data directly within the diagram:

1. Hover to Inspect the Numbers

You don’t need to guess what the overlaps represent. The report offers two distinct views depending on where you place your cursor:

View Exclusive Numbers: Move your pointer to the centre of a specific segment circle. This shows you the data for users who belong only to that segment and do not overlap with the others.

View Inclusive Numbers: Move your pointer to the border where segments cross. This highlights the “inclusive members”—the users who sit in the overlap between two or three of your segments.

2. Right-Click to Take Action

The real power of this report lies in the right-click menu.

If you identify a crossover that looks valuable—for example, users from a specific traffic source who also purchased a specific product category you can right-click directly on that intersection.

This gives you two options:

View Users: This opens the User Exploration report, allowing you to see the individual actions of the anonymous users within that overlap. It is useful for understanding the specific journey a user took.

Create Segment from Selection: This is the feature you will likely use most. It immediately opens the segment builder with your conditions pre-loaded.

From here, you can save this group as a new segment to apply to other reports, or create a targeted Audience for retargeting campaigns (e.g., creating a list of “High-Value Mobile Users” to export to Google Ads).

3. Refining the Data Table

Below the visualisation, the data table provides the raw numbers. You have control here too:

Breakdowns: You can add dimensions (like ‘Country’ or ‘Device Category’) to break the table data down further.

Rows: You can adjust the “Start row” and “Show rows” settings to focus on specific chunks of data, or display up to ten metrics to get a broader view of performance.

Breakdown in Segment Overlap

Right-Click to Build Audiences

This is the part that adds real strategic value.

When you look at the diagram, you can hover your mouse over specific sections.

Hover over a specific segment circle: You see the exclusive numbers for that segment.

Hover over the overlapping borders: You see the inclusive numbers—the users who sit in both (or all three) camps.

But here is the clever bit.

If you spot an overlap that looks promising—say, users who visited your blog AND added an item to cart—you can right-click directly on that intersection.

From that menu, you can select “Create segment from selection“.

This opens the segment builder with those conditions pre-loaded.

You can then save this as a new Audience.

If you’ve linked GA4 to Google Ads, this audience is immediately available for retargeting.

It turns analysis into action in about three clicks.

Use Cases

It’s easy to get stuck on “what” the tool does, but let’s look at “why” you’d use it. Here are some scenarios where I’ve found this report particularly useful.

1. The E-commerce “Sweet Spot”

Combine Demographics, Device Type, and Revenue. You might find a significant overlap between females aged 25-34, using iOS devices, who generate high revenue.

Once you identify this cluster, you can build an audience specifically for them and increase your ad spend on mobile placements for that demographic.

2. Content-to-Conversion Analysis

Combine Blog Visitors (users who viewed a blog page) and Purchasers.

Does your content strategy actually drive sales?

This overlap will show you exactly how many people entered via the blog and eventually converted.

If the overlap is small, you might need to look at your internal linking or CTAs.

Sharing Your Findings

Analysis is rarely a solo sport.

You’ll often need to show a client or a Head of Marketing why you want to change the budget.

In the top right of the exploration, there is a Share icon.

This allows you to share the exploration in Read-Only mode.

It’s perfect for keeping your peers informed without worrying that someone will accidentally delete your carefully configured segments.

Sharing Report in GA4

Summary

The Segment Overlap tool is a fast, visual way to understand complex user behaviours. It prevents you from making assumptions about your audience and helps you build data-backed segments for your marketing campaigns.

Frequently Asked Questions

Can I compare more than three segments?

No, the limit for the visualisation is three segments. If you need to analyse more complex combinations, you may need to use the Free Form exploration or export the data to BigQuery.

Why don’t the numbers in the table match the diagram exactly?

The diagram shows the visual overlap of user counts. The table below provides a breakdown based on the dimensions you added. Always check if you are looking at “Active Users” or “Total Users” as your metric, as this often accounts for discrepancies.

Can I use this for non-e-commerce sites?

Absolutely. You can use it to track overlaps between traffic sources, content engagement (e.g., downloaded a PDF vs. watched a video), or any custom event you have set up.

Kyle

Author

Hello, I'm Kyle Rushton McGregor!

I’m an experienced GA4 Specialist with a demonstrated history of working with Google Tag Manager and Looker Studio. I’m an international speaker who has trained 1000s of people on all things analytics.

Find out more About me
Scroll to Top