Core Web Vitals have evolved since their introduction as ranking signals in 2021. LCP replaced FID with INP in 2024. Google has explicitly stated that the Web Performance Working Group continues researching additional metrics and that CWV will evolve as measurement technology and web patterns change. Building for current CWV thresholds is necessary — building for the direction CWV is evolving is strategically advantageous.

The Current State of Core Web Vitals in 2026

The three current Core Web Vitals:

LCP (Largest Contentful Paint): Measures how quickly the largest content element renders. Good threshold: under 2.5 seconds. As covered in our guide to mobile CWV fixes, image optimisation and server response time are the primary improvement levers.

INP (Interaction to Next Paint): Measures responsiveness to all interactions throughout the page session. Good threshold: under 200ms. As covered in our guide to advanced speed optimisation, JavaScript main thread optimisation is the primary improvement lever. INP replaced FID specifically because it measures all interactions, not just the first.

CLS (Cumulative Layout Shift): Measures visual stability — how much content unexpectedly shifts during loading. Good threshold: under 0.1. Image dimension specification and ad container sizing are the primary causes.

What Google Has Signalled About CWV Evolution

Google's Web Performance Working Group and Chrome team have provided directional signals about future metric development through blog posts, conference talks, and specification documents:

Smoothness metrics. Google has researched metrics for animation smoothness and scroll jank — how smoothly pages animate and scroll. The experimental Smoothness metric measures whether JavaScript execution or rendering issues cause visual stutter. Sites that cause visual jank during scroll or animation provide worse user experiences that current CWV does not specifically capture. Future metric candidates include frame rendering consistency during scroll-heavy interactions.

Network resilience. Current CWV is measured on median user network conditions. Google has researched measuring performance on slower connection conditions — specifically targeting the gap between average performance and performance for users on 3G or degraded connections. Sites that degrade dramatically on slower networks may face future metrics that measure performance distribution, not just median performance.

Energy efficiency. With increasing sustainability focus and the proliferation of battery-powered mobile devices, energy consumption per page load is an emerging research area. Pages that drain battery through excessive JavaScript execution, unnecessary animations, or inefficient rendering patterns may be evaluated through energy efficiency metrics in future updates.

New Device Form Factors

Foldable phones, tablets, smartwatches, and AR/VR interfaces create new form factor challenges that current CWV does not specifically address. Google's measurement infrastructure is expanding to capture field data from diverse device types. The sites that perform well across these new form factors — through responsive layouts that genuinely adapt, not just desktop-shrunken content — are building the performance profile that serves future measurement regardless of specific metric definitions.

What to Build Now for Future Readiness

The investments that serve current CWV and future metric evolution simultaneously:

  • Minimise main thread JavaScript execution — serves INP now and smoothness metrics in future
  • Serve appropriately sized resources for every connection type — serves current LCP and future resilience metrics
  • Eliminate unnecessary animations and heavy rendering — serves energy efficiency directions
  • Responsive design that genuinely adapts to diverse viewports — serves new form factor metrics
  • Server-side rendering for critical content — reduces all rendering-dependent metric risks

Summary

Core Web Vitals will evolve toward smoothness measurement, network resilience distribution, energy efficiency, and diverse device form factor coverage. The current CWV investments — JavaScript optimisation, image optimisation, visual stability — serve all directional future developments. Use our speed tool to maintain current CWV excellence while building toward the performance profile that will serve future metric evolution: minimal JavaScript, efficient rendering, genuine responsive adaptation, and consistent performance across connection quality levels.

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