Question 1

What is Core Web Vitals optimization?

Accepted Answer

Core Web Vitals optimization is the process of improving the three user-experience metrics Google measures from real visits: loading speed (LCP), responsiveness (INP), and visual stability (CLS). It covers code, rendering strategy, images, fonts, third-party scripts, and hosting.

Question 2

What are good Core Web Vitals scores?

Accepted Answer

A page is rated good when LCP is 2.5 seconds or less, INP is 200 milliseconds or less, and CLS is 0.1 or less. These are assessed at the 75th percentile of real-user data, separately for mobile and desktop.

Question 3

Does my frontend framework affect Core Web Vitals?

Accepted Answer

Yes. Frameworks influence how much JavaScript the browser must download and run, and how much of the page is rendered on the server versus the client. That affects all three metrics, with INP usually the most sensitive. Framework choice sets the starting point, but implementation still decides the final result.

Question 4

What percentage of websites pass Core Web Vitals?

Accepted Answer

A January 2026 analysis of Chrome field data found 55.7% of web origins pass all three thresholds. Mobile is lower: about 48% of sites passed in the 2025 Web Almanac.

Question 5

Do Core Web Vitals affect SEO rankings?

Accepted Answer

They are one of many page experience signals, and good scores do not guarantee higher rankings. The more reliable benefit is commercial: faster, steadier pages tend to reduce bounce and improve conversion on the traffic you already have.

Question 6

What is StreakJS and how does it help with Core Web Vitals?

Accepted Answer

StreakJS is Valoriz's server-first web performance framework. It combines server rendering and pre-rendered pages with minimal client-side JavaScript, lazy-loading control, automated CDN delivery, and live performance monitoring. Those features target LCP and INP by reducing the work done in the browser.

Core Web Vitals Optimization: How Your Frontend Framework Affects Website Performance