What is CLS by device brand
CLS by device brand shows Cumulative Layout Shift (CLS) grouped by known hardware categories — including specific iPhone models, Android phones, Mac and Windows desktops, and Linux systems.
Unlike general categories like “Mobile” or “Tablet,” this view reflects real device families, helping you detect whether layout instability is concentrated on certain devices — like an Android midrange phone, an older Windows PC, or a Safari-powered iPhone.
This lens is especially useful when debugging device-specific UI bugs, testing responsive behavior across screen sizes, or identifying brand-level rendering quirks that lead to layout shifts.
Healthy CLS by device brand sample
A healthy CLS by device brand chart shows green across major device types, even if there’s minor variation. For instance:
iPhones and Macs tend to have strong layout stability if your site is optimized for Safari.
Android phones may vary depending on screen density, OS version, or vendor UI layers.
Desktops like Windows and Linux generally handle layout well unless content is loaded late or rendered without guardrails.
As long as none of the devices display consistent yellow or red CLS, and your performance aligns with your audience mix, you’re in a safe zone.
Unhealthy CLS by device brand sample
High CLS scores from specific device groups can reveal deeper frontend or styling issues. For example:
iPhones: Often sensitive to missing height constraints, dynamic font scaling, or Safari quirks around fixed elements.
Android phones: May trigger shifts from delayed images, lack of space reservation, or rendering inconsistencies across Chrome versions.
Windows or Linux desktops: Shifts can occur from late-loading fonts, viewport zoom scaling, or content injected too early.
Macs: While rare, shifts may come from hover-based interactions, unoptimized grid layouts, or scroll-based animations.
Brand-specific rendering issues can often go unnoticed unless broken down like this.
Resolving unhealthy CLS by device brand
Go-to action plan to resolve an unhealthy CLS by device brand:
Ask Uxi to analyze your CLS by device brand values and suggest improvements
Use Filters to isolate the device group with the worst layout stability and cross-reference other lenses like viewport size, zoom, or interaction type.
Simulate CLS of the suspected lens to see if fixing it will resolve the CLS by device brand. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by device brand values
Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.
Try it yourself
Discover how your website performs with real user data.