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Web Page Optimization Is Key for Google Algorithms

Google’s Web Vitals initiative provides guidance about web page performance quality signals that are essential for all sites to attain in order to deliver a superior user experience on the web and provide better SEO page search rankings. Core Web Vitals are a subset of performance metrics that apply to all web pages that should be measured by all site owners, with support across all Google tools. It will be part of Google’s “page experience” score to establish a ranking factor. These metrics include loading performance (how fast does web page content appear on the screen?), responsiveness (how fast does the page react to user input?), and visual stability (does content move around on the screen while loading the page?).

Google has defined three Core Web Vitals metrics to specifically quantify these page experiences:


Largest Contentful Paint (LCP)

Largest Contentful Paint (LCP) measures how long it takes for the largest piece of content (like an image or block of text) to appear on the screen. A good score indicates that your site loads quickly for the user., and it accounts for around 25% of the Page Insight score. A slow site can lead to frustration for users. An ideal LCP measurement is 2.5 seconds or faster, providing a good user experience and optimal SEO performance. First Contentful Paint (FCP) is related to LCP but is a non-Core Web Vital scoring metric that measures the time from when a page starts loading to when any part of that page's content is rendered on the screen. FCP is a user-centric metric for measuring page load time and speed. Google has specific LCP guidelines. They break LCP speed down into three buckets: Good, Needs Improvement, and Poor.


First Input Delay (FID)

First Input Delay (FID) measures the length of time it takes for the site to respond to an initial user action (such as a button click) An ideal measurement is less than 100 ms, which reflects in a very usable web page and positive user experience. Time to Interactive (TTI) is a related non-core web vitals metric that measures the time from when the page starts loading to when it is capable of reliably responding to user inputs.


Cumulative Layout Shift (CLS)

Cumulative Layout Shift (CLS) measures the amount of unexpected layout shift of visual page content. For example, does content regularly move around on the screen while it is still loading?An ideal measurement is less than 0.1 as this reflects a stable page with good experience for the user.

Measuring Core Web Vital Performance With Synthetic Transaction Testing

ThousandEyes Network and Application Synthetics with browser transaction testing provides a detailed understanding of real-time website performance by measuring specific web events. This JavaScript transaction engine transaction testing emulates a user's journey over a Chrome browser and walks through each step of a synthetic transaction. This capability makes it possible for you to measure key metrics associated with Core Web Vitals by:

  • Taking advantage of the programmability of JavaScript-based workflow creation to customize the navigation path, test for asserts and conditionals
  • Defining custom markers for critical points in the user interface that represent key Core Web Vital metrics
  • Digging into the details of transaction tests, which are a series of page load tests interspersed with emulated user interactions, like typing in fields and clicking buttons.
  • Playing back scripted transactions and save snapshots at customizable intervals to debug failed transactions
  • Scheduling tests with flexible round-robin scheduling that allows for granular testing up to 1 minute

Page Load Metrics

Page load tests enable you to accurately measure and benchmark page view performance and set alert thresholds for page load times. HTTP Server tests enable you to understand how DNS, SSL, Receive and HTTP phases impact page performance to quickly identify any server/infrastructure improvements that may also be needed, in addition to fine tuning web page elements.

Web Component Waterfalls

Detailed waterfalls show the sequential fetching and loading of web page components, so you can identify performance issues related to errors, bottlenecks, and the impact of third-party API services.

Website Monitoring with ThousandEyes

ThousandEyes monitors the delivery of your websites and online applications so you can understand how HTTP, page load and transaction performance is affected by the network, and how it stacks up against other similar services.

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Why ThousandEyes?

Customize dashboards and alerts

Create dashboards and proactively monitor Core Web Vitals performance metrics, and receive alerts when page loads exceed a defined threshold.

Monitor from where your users are

Measure page load metrics from Cloud Agents and Enterprise Agents related to Core Web Vitals performance metrics measured by Google.

Take advantage of vantage points deployed worldwide

Cloud Agents are pre-deployed by ThousandEyes on servers around the world—in nearly 200 cities in 60 countries.

Start Monitoring Web Performance for Core Web Vitals Using ThousandEyes!

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