Performance Metrics

Important

The Performance widget is designed exclusively for website analysis and is not applicable for mobile application performance monitoring.

Overview

Clarity's Performance widget is a fundamental feature designed for website owners to monitor and enhance the site's user experience. This widget is aligned with the industry standards for core web vitals, offering insights into critical metrics that affect loading performance, interactivity, and visual stability.

Performance widget.

Core web vitals

Core Web Vitals are key metrics crucial for superior user experience on your website that includes:

  • Largest Contentful Paint (LCP): LCP metric measures the loading performance of the primary content of a page. An ideal LCP occurs within 2.5 seconds of the initiation of page loading.

  • First Input Delay (FID): FID measures the duration from the initial user interaction with your site to the point at which the browser can respond. The target for FID is 100 milliseconds or less.

  • Cumulative Layout Shift (CLS): CLS assesses the stability of your page layout. CLS with 0.1 seconds or less is considered good.

Understanding the performance widget

Note

LCP, FID, and CLS displayed here are the 75th percentile. Selecting heatmaps or recordings icon filters the result with the numbers that are larger than the ones on the widget.

The performance widget contains two tabs:

  • Performance Overview: This tab instantly provides comprehensive scores for your website. It also includes the performance score breakdown with an option to view related recordings and heatmaps.

    Performance overview.

  • URL Performance: Explore every page for in-depth insights and trend analysis. The URLs can be sorted based on Score, LCP, FID, and CLS. Watch the related recordings and heatmaps to analyze further.

    URL performance.

By default, performance overview tab is pinned. You can change the default tab as follows:

Go to Card data -> Customize dashboard -> Select default tab. Choose performance overview or url performance.

Change default tab.

Identifying causes and solutions

LCP

Causes: Large images, slow server responses, or render-blocking JavaScript and CSS.

Solutions: Server upgrades, image optimization, and minimizing or deferring JavaScript and CSS.

FID

Causes: Often caused by heavy JavaScript execution.

Solutions: Reducing, deferring, or asynchronously loading JavaScript; employing web workers.

CLS

Causes: Dynamic content loading, unassigned image dimensions, and ad or embed shifts.

Solutions: Specifying image and video dimensions, static space allocation for ads and embeds.

How to use the widget data?

  • LCP: Watch user session recordings on pages with the highest LCP to observe user responses to slow loading times. Assess whether users choose to wait or exit the page. Implement optimizations such as image compression or code reduction based on your insights.

  • FID: Watch recordings to observe user interactions with elements on pages with low FID scores (For example: FID < 300 ms indicates that there's a need for improvement. For more information, see Filters). Look for signs of frustrations or instances repeated clicks. Use heatmaps to identify areas with high user activity and potential bottlenecks. Optimize JavaScript execution and streamline interactive elements.

  • CLS: Identify problematic pages and review recordings to observe instances where users experience unexpected layout shifts. Analyze heatmaps for affected areas, especially where users clicked or attempted to interact. Stabilize layout elements and validate changes through the widget. Confirm users experience improvements in new recordings and heatmaps.

FAQ

For more answers, refer to Insights FAQ.

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