How to add a comparison to your reports in Google Analytics 4

What are comparisons in Google Analytics 4?

Comparisons in Google Analytics 4 are powerful tools that allow you to compare different subsets of your data side by side within standard reports. 

When you add comparisons to a report, GA4 displays multiple data sets simultaneously, making it easy to spot trends, differences, and insights between different user groups or conditions. For example, you can instantly see how mobile users behave compared to desktop users, or how organic traffic performs against paid traffic.

Key benefits of GA4 comparisons:

• Instant side-by-side data analysis
• No need to switch between different reports or export data
• Visual colour-coding for easy identification
• Persistent across multiple standard reports
• Can be saved for future use (2024+ feature)

Why use comparisons instead of filters?

Whilst GA4 offers both filters and comparisons, comparisons provide distinct advantages for data analysis:

Comparisons vs filters

• Side-by-side view: Comparisons show multiple data sets simultaneously, whilst filters show only one subset at a time
• Persistence: Comparisons carry over as you navigate between reports, whilst filters need to be reapplied
• Visual distinction: Each comparison gets its own colour coding in charts and tables
• Efficiency: Faster analysis without switching between filtered views

When to use comparisons

Comparisons are ideal for:

• Analysing performance differences between user segments
• Comparing traffic sources (organic vs paid vs social)
• Evaluating device performance (mobile vs desktop vs tablet)
• Geographic analysis (comparing different countries or regions)
• Time-based comparisons (though date range comparisons work differently)
• A/B testing analysis with custom audience segments

How to access comparisons in GA4

Comparisons are available in most standard reports within the "Reports" section of GA4. Here's how to access them:

Step 1: Navigate to a standard report

Comparisons work in standard reports such as:

• Reports snapshot
• User acquisition
• Traffic acquisition
• Engagement reports
• Monetisation reports
• Demographics and tech reports

Step 2: Locate the comparison controls

Once in a standard report, look for the comparison controls at the top of the report:

• "Add comparison" button: Usually appears as a "+" symbol or text link
• "Edit comparisons" icon: Pencil or gear icon for managing existing comparisons
• Active comparisons: Displayed as coloured labels showing current comparisons

Important note: Comparisons are not available in the Explore section or overview reports. For detailed analysis in Explore, you'll need to use segments instead.

Adding your first comparison

Let's walk through creating a basic comparison to see how mobile traffic performs compared to desktop traffic.

Step-by-step process

1. Open a standard report (e.g., Reports > Acquisition > User acquisition)
2. Click "Add comparison" in the top-left area of the report
3. Configure the first comparison:
   • Choose dimension: "Device category"
   • Select match type: "exactly matches"
   • Enter value: "mobile"
   • Click "Apply"
4. Add a second comparison:
   • Click "Add comparison" again
   • Choose dimension: "Device category"
   • Select match type: "exactly matches"
   • Enter value: "desktop"
   • Click "Apply"
5. Remove "All Users" by clicking the "X" on its label

Understanding the results

Once applied, you'll notice several changes to your report:

• Coloured labels: Each comparison appears as a coloured label at the top
• Chart updates: Line charts show multiple coloured lines
• Table changes: Data tables display side-by-side columns
• Card modifications: Summary cards split to show comparison data

Using prebuilt comparisons

Google Analytics 4 includes prebuilt saved comparisons for frequently needed use cases, including comparisons for direct traffic, organic traffic, web traffic, and mobile traffic. These save time and provide standardised analysis frameworks.

Available prebuilt comparisons

• Direct Traffic: Users who visited your site directly
• Organic Traffic: Users from organic search results
• Web Traffic: All website visitors (excluding app users)
• Mobile Traffic: Users on mobile devices

How to apply prebuilt comparisons

1. Navigate to any standard report
2. Click "Add comparison"
3. Look for the "Saved comparisons" section
4. Select from the available prebuilt options
5. Click "Apply" to add to your report

Pro tip: Start with prebuilt comparisons to understand how they're constructed, then use them as templates for creating your own custom comparisons.

Creating custom comparisons

Custom comparisons allow you to analyse specific segments relevant to your business needs. Here's how to create sophisticated custom comparisons.

Understanding comparison logic

GA4 comparisons use specific logic for multiple conditions: Multiple values for the same condition are evaluated with OR logic (e.g., Platform = Android OR iOS), whilst multiple conditions within the same comparison are evaluated with AND logic.

Match types available

• Exactly matches: Precise value matching
• Does not exactly match: Excludes specific values
• Contains: Partial string matching (case sensitive)
• Does not contain: Excludes partial matches

Example: Comparing high-value countries

Let's create a comparison for analysing traffic from your top-performing countries:

1. Start the comparison creation process
2. Configure the condition:
   • Dimension: "Country"
   • Match type: "exactly matches"
   • Values: "United Kingdom", "United States", "Germany"
3. Add additional conditions if needed (up to 4 more conditions)
4. Apply the comparison

Advanced custom comparison ideas

• Page performance: Compare specific page paths using "Page path and screen class"
• Campaign analysis: Compare different UTM campaigns or sources
• User engagement: Compare users with different session durations
• E-commerce analysis: Compare purchasers vs non-purchasers

Using saved comparisons (2024+ feature)

Google Analytics 4 introduced saved comparisons in 2024, allowing users to save comparison configurations for future use, significantly saving time for frequent segment analysis. This feature addresses one of the major limitations of the original comparisons tool.

Benefits of saved comparisons

• Time efficiency: No need to recreate complex comparisons
• Consistency: Standardised analysis across different time periods
• Collaboration: Share comparisons with team members
• Advanced conditions: Access to additional dimensions like Page path and screen class that weren't available before

How to save a comparison

1. Create your comparison using the steps above
2. Instead of clicking "Apply", click "Save"
3. Enter a descriptive name for your comparison
4. Add an optional description for context
5. Click "Confirm" to save

Managing saved comparisons

To manage your saved comparisons:

1. Go to Admin > Data display > Comparisons
2. View all saved comparisons in your property
3. Use the three-dot menu to edit, duplicate, or delete comparisons
4. Check quota usage (up to 200 comparisons per property)

Permission requirements: You must be an Editor or above at the property level to save a comparison.

Advanced comparison conditions

For sophisticated analysis, you can create comparisons with multiple conditions and complex logic.

Using multiple conditions

You can add up to 5 conditions per comparison. Here's an example for analysing engaged mobile users from specific countries:

1. Condition 1: Device category exactly matches "mobile"
2. Condition 2: Country exactly matches "United Kingdom" OR "United States"
3. Condition 3: Session duration contains "00:01" (sessions longer than 1 minute)

Audience-based comparisons

You can leverage existing audience lists as conditions within saved comparisons, allowing for sophisticated comparisons based on your most valuable user segments.

To create an audience-based comparison:

1. First, create an audience in GA4 (Admin > Audiences)
2. In your comparison, select "Audience name" as the dimension
3. Choose your created audience as the value
4. This enables comparisons like "High-value users" vs "All users"

Complex condition examples

• Engaged social traffic: Source contains "facebook" OR "twitter" AND Session duration > 2 minutes
• High-value mobile commerce: Device = "mobile" AND Purchase revenue > 50 AND Country = "UK"
• Content engagement: Page path contains "/blog/" AND Scroll depth > 75%

Working with multiple comparisons

GA4 allows you to run multiple comparisons simultaneously, enabling complex multi-dimensional analysis.

Best practices for multiple comparisons

• Limit to 3-4 comparisons: Too many can make charts difficult to read
• Use logical groupings: Related comparisons work better together
• Consider colour coding: GA4 automatically assigns colours, but similar comparisons may get similar colours
• Remove "All Users": Often not needed when comparing specific segments

Example: Complete device and traffic source analysis

Create these four comparisons for comprehensive analysis:

1. Mobile organic: Device = "mobile" AND Source = "google"
2. Desktop organic: Device = "desktop" AND Source = "google"
3. Mobile paid: Device = "mobile" AND Medium = "cpc"
4. Desktop paid: Device = "desktop" AND Medium = "cpc"

Managing comparison overload

If your reports become cluttered:

• Click the "X" on comparison labels to remove them temporarily
• Use the "Edit comparisons" icon to modify or remove comparisons
• Consider creating separate saved comparisons for different analysis needs

Editing and managing comparisons

GA4 provides several options for modifying and managing your comparisons after they're created.

Quick editing options

• Remove a comparison: Click the "X" on its label
• Edit a specific comparison: Click directly on the comparison label
• Edit all comparisons: Click the "Edit comparisons" icon in the top-right

Advanced editing through Admin

For saved comparisons, use the Admin interface:

1. Navigate to Admin > Data display > Comparisons
2. Find your saved comparison in the list
3. Click the three-dot menu for options:
• Edit: Modify conditions and settings
• Duplicate: Create a copy to modify
• Delete: Remove permanently

Troubleshooting comparison edits

If you can't edit a comparison:

• Check your permission level (Editor+ required for saved comparisons)
• Verify the comparison isn't a prebuilt default (these cannot be edited)
• Try duplicating and editing the copy instead

Practical comparison examples

Here are real-world scenarios where comparisons provide valuable insights:

E-commerce analysis

Goal: Compare purchasing behaviour across devices

Comparisons to create:

• Mobile purchasers: Device = "mobile" AND Event = "purchase"
• Desktop purchasers: Device = "desktop" AND Event = "purchase"
• Tablet purchasers: Device = "tablet" AND Event = "purchase"

Insights gained: Conversion rates, average order values, and purchase patterns by device

Content performance analysis

Goal: Compare blog performance vs product pages

Comparisons to create:

• Blog traffic: Page path contains "/blog/"
• Product traffic: Page path contains "/products/"
• Landing page traffic: Page path exactly matches "/"

Insights gained: Engagement rates, bounce rates, and conversion paths for different content types

Marketing campaign analysis

Goal: Compare paid campaign performance

Comparisons to create:

• Google Ads: Source = "google" AND Medium = "cpc"
• Facebook Ads: Source = "facebook" AND Medium = "cpc"
• LinkedIn Ads: Source = "linkedin" AND Medium = "cpc"

Insights gained: Cost-effectiveness, engagement quality, and conversion rates by platform

Geographic performance analysis

Goal: Compare performance across key markets

Comparisons to create:

• UK market: Country = "United Kingdom"
• US market: Country = "United States"
• EU markets: Country = "Germany" OR "France" OR "Spain"

Insights gained: Regional preferences, conversion rates, and market-specific behaviour patterns

Limitations and troubleshooting

Understanding GA4 comparison limitations helps you work more effectively and troubleshoot common issues.

Key limitations

• Standard reports only: Comparisons can't be used in Explorations for deeper analysis - use segments instead
• Dimension compatibility: Some dimensions aren't available in all reports
• Quota limits: Maximum 200 saved comparisons per GA4 property
• Real-time limitations: Some comparisons may not work in real-time reports
• Data sampling: Complex comparisons might trigger data sampling in high-traffic properties

Common troubleshooting issues

Blank comparison cards

If a report doesn't support a condition (for example, the report doesn't include one of the dimensions), then a blank card appears for that comparison.

Solutions:

• Choose different dimensions for the condition
• Remove the problematic condition
• Switch to a compatible report

Missing dimension values

Not all dimension values may be available. Some dimensions are not allowed to be excluded, whilst others are not available due to your configuration.

Solutions:

• Check data collection setup
• Verify dimension spelling and formatting
• Try alternative dimensions with similar data

Comparisons not persisting

If comparisons disappear between reports:

• Ensure you're staying within standard reports
• Avoid switching to Explore section
• Check if you've accidentally removed them
• Consider saving comparisons for permanent access

Performance considerations

• Complex conditions: Multiple conditions may slow report loading
• Large audiences: Audience-based comparisons might trigger sampling
• Historical data: Some audience comparisons only work from creation date forward

Best practices for using comparisons

Maximise the effectiveness of your GA4 comparisons with these best practices:

Strategic comparison planning

• Start with business questions: Define what you want to learn before creating comparisons
• Use prebuilt comparisons as templates: Understand their structure before creating custom ones
• Document your comparisons: Use descriptive names and descriptions for saved comparisons
• Regular review: Audit saved comparisons quarterly to remove outdated ones

Technical best practices

• Test in low-traffic periods: Complex comparisons may load faster during off-peak times
• Use exact matches when possible: More precise than partial matching and often faster
• Monitor quota usage: Keep track of your saved comparison count
• Backup important comparisons: Document complex comparison logic externally

Analytical best practices

• Combine with date ranges: Use GA4's date comparison feature alongside segment comparisons
• Focus on actionable insights: Choose comparisons that lead to business decisions
• Validate with Explore: Use segments in Explore for deeper analysis of interesting comparison results
• Share findings effectively: Export comparison reports for stakeholder presentations

Workflow optimisation

• Create comparison sets: Group related saved comparisons for different analysis types
• Use consistent naming: Develop a naming convention for easy identification
• Train team members: Ensure colleagues understand how to use saved comparisons
• Regular reporting: Set up recurring analysis using consistent comparisons

Integration with other GA4 features

• Audience building: Use comparison insights to create more targeted audiences
• Goal tracking: Monitor conversion goals across different comparisons
• Attribution analysis: Combine comparisons with attribution reports for comprehensive insights
• Looker Studio: Export comparison data for advanced visualisation

Future-proofing your comparisons

As GA4 continues to evolve:

• Stay updated with new dimension releases
• Regularly review Google's comparison feature updates
• Test new comparison capabilities as they're released
• Adapt comparison strategies based on data collection changes

Remember: Comparisons are most effective when they directly support your business objectives. Focus on creating comparisons that help you understand your users better and make data-driven decisions for growth.

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