August 26, 2020

Real-user monitoring support for W3C trace context and Google Core Web Vitals

We've added support for W3C trace context and Google Core Web Vitals!

While it has a new home within our Full-Stack Observability product, we’ve made improvements to our Browser agent and Real User Monitoring (RUM) capabilities, including:

These new improvements help both frontend and web developers, who are increasingly spending time in incident resolution, focus on their main role of solving problems with software.

In our continued standardization of W3C trace context, our Browser agent now offers the standard trace context. W3C trace context enables cross-vendor interoperation of traces and helps ensure that, when using distributed tracing, you can troubleshoot services instrumented with agents from other vendors without risking broken or incomplete traces. Additionally, this also ensures that you’ll be able to reliably traverse third-party components, including proxies and API gateways.

Additionally, W3C trace context offers the same advantages when using open source tracers, enabling you to incorporate tracing telemetry data from any source, at any time, and to implement traces across highly-distributed application environments.

See our docs for more information about standard trace context.

We're excited to announce the release of Cumulative Layout Shift (CLS), the third and final metric in Google Core Web Vitals. This metric is an important user-centric metric for measuring visual stability, because it helps quantify how often users experience unexpected layout shifts. A low CLS score helps ensure that your page is delightful and visually stable.

The current set of 2020 Core Web Vitals focuses on three aspects of the user experience: loading, interactivity, and visual stability. These are the following metrics and their thresholds:

  • Largest Contentful Paint (LCP): measures loading performance. To provide a good user experience, LCP should occur within 2.5 seconds of when the page starts loading.
  • First Input Delay (FID): measures interactivity. To provide a good user experience, pages should have a FID of less than 100 milliseconds.
  • Cumulative Layout Shift (CLS): measures visual stability. To provide a good user experience, pages should maintain a CLS of less than 0.1.

For each of the above metrics, to ensure you're hitting the recommended target for most of your users, a good threshold to measure is the 75th percentile of page loads, segmented across mobile and desktop devices. To learn more about the research and methodology behind these recommendations, see: Defining the Core Web Vitals metrics thresholds. Tools that assess Core Web Vitals compliance should consider a page passing if it meets the recommended targets at the 75th percentile for all of these three metrics.

For more on measuring Cumulative Layout Shift, see our docs.