What is Google Core Web Vitals
Google’s mission is to provide the best experience for users of its search engine.
Core Web Vital provides unified guidance for quality signals that are essential to delivering a great user experience on the web.
Core Web Vitals are the subset of Web Vitals that apply to all site pages, should be measured by all webmaster/site owners, and soon will be surfaced across all Google tools that measure webpage performance.
The metrics that makeup Core Web Vitals will evolve over time. The current Core Web Vitals set for 2020 focuses on three aspects of user experience.
– Loading
– Interactivity
– Visual stability
In Google’s own words
The page experience signal measures aspects of how users perceive the experience of interacting with a web page. Optimizing for these factors makes the web more delightful for users across all web browsers and surfaces, and helps sites evolve towards user expectations on mobile. We believe this will contribute to business success on the web as users grow more engaged and can transact with less friction.
Google Core Principles of Search
- Focus on the user
- Most relevant with highest quality information
- Algorithmic approach
- Rigorously test every change
What is Largest Contentful Paint (LCP)
LCP measures the loading performance of a web page.
To provide good user experience, LCP should occur within 2.5 seconds of when the page first starts loading.
Common causes of a poor LCP:
- Slow server response times
- Render-blocking JavaScript and CSS
- Client-side rendering
- Slow resource load times
What is First Input Delay (FID)
First Input Delay (FID) measures interactivity.
To provide good user experience, Google recommends, pages should have an FID of less than 100 milliseconds.
Common causes of a poor FID
The main cause of a poor First Input Delay (FID) is heavy JavaScript execution. Optimizing, how JavaScript compiles, parses, and executes on your webpage will directly reduce FID.
To improve JavaScript execution time:
- Reduce JavaScript execution time
- Break up Long Tasks
- Optimize your page for interaction readiness
- Use a web worker
What is Cumulative Layout Shift (CLS)
Cumulative Layout Shift (CLS) measures visual stability.
To provide good user experience, Google recommends, Pages should maintain a CLS of less than 0.1
Common causes of a poor CLS
The most common causes of a poor CLS are:
- Images without dimensions
- Ads, embeds, and iframes without dimensions
- Web Fonts causing FOIT/FOUT
- Actions waiting for a network response before updating DOM
- Dynamically injected content
Why use Core Web Vitals
Longer page load times have a severe effect on bounce rates.
Google announced Core Web Vitals will become a ranking factor in 2021. SEO managers & Developers have several months to worry about.
There are many tools available such as Google Page Speed Insights to measure and report on performance. With Core Web Vitals, Google aims to simplify the landscape and help sites focus on the metrics that matter most.
In conclusion
Core Web Vitals ensures the page provides a great user experience, focusing on the aspects of loading, interactivity, and visual stability.
Google wants quality pages that load quickly on its search engine.