Device Size Filtering

What is device size filtering?

Device size filtering lets you see your split test results broken down by screen size. Filter by mobile, tablet, or desktop and see exactly how each variation is performing on that device.

Before v2.5.1, getting per-device results meant creating separate tests for each screen size. Now you do it inside a single test.

Why device size matters in split testing

Visitors on mobile and desktop behave differently. A variation can win on desktop and lose on mobile at the same time. Without filtering, those results get averaged together and the signal disappears.

Device size filtering surfaces that. You can see where each variation is actually winning.

What the filtered results show

Filter by device and your results update to show:

• Visits per variation
• Conversions per variation
• Conversion rate per variation
• Statistical confidence
• Revenue per variation (if Use Order Value is enabled)
• Winner detection status for that segment

Winner detection requires 95% confidence, a minimum of one week of runtime, and at least 50 visits per variation in that segment. If a segment does not have enough data yet, the underpowered badge will show.

Where device size filtering is available

Filtering works across every way you view your results:

• The test results dashboard
• Public shareable reports
• REST API
• WP-CLI
• MCP

Things to keep in mind

Smaller segments take longer to reach confidence. Filtering splits your traffic into smaller groups. A test with enough overall data may still show as underpowered on a specific device if that segment has fewer than 50 visits per variation. That is expected behavior.

Device size filtering is available on Ultimate only. It is not included in the Free Lite plan.