Google posted an FAQ around Core Web Vitals and the upcoming Google Page Experience update launching in May 2021. Google's Cheney Tsai said the company has compiled some of the most frequently asked questions about Core Web Vitals and Page Experience. This was not posted as a blog post or help document but in the Google Webmaster Help forums.
Note: Google said this page experience update will only be used as a ranking signal on mobile search, not desktop search - at least not yet. Here is that list:
Q: What are the metrics? Why are they relevant to users?
A: User-centric metrics are a critical tool in understanding, measuring and improving the user experience of your website. Largest Contentful Paint measures how quickly users see content. First Input Delay measures how responsive a site is to user input like tapping a button or entering data in a form. Cumulative Layout Shift measures how often elements of the page move around while the user is trying to read or interact with it.
Q: Is Google recommending that all my pages hit these thresholds? What’s the benefit?
A: We recommend that websites use these three thresholds as a guidepost for optimal user experience across all pages. Core Web Vitals thresholds are assessed at the per-page level, and you might find that some pages are above and others below these thresholds. The immediate benefit will be a better experience for users that visit your site, but in the long-term we believe that working towards a shared set of user experience metrics and thresholds across all websites, will be critical in order to sustain a healthy web ecosystem.
Q: If I built AMP pages, do they meet the recommended thresholds?
A: There is a high likelihood that AMP pages will meet the thresholds. AMP is about delivering high quality, user-first experiences; its initial design goals are closely aligned with what Core Web Vitals measure today. This means that sites built using AMP likely can easily meet Web Vitals thresholds. Furthermore, AMP's evergreen release enables site owners to get these performance improvements without having to change their codebase or invest in additional resources. It is important to note that there are things outside of AMP’s control which can result in pages not meeting the thresholds, such as slow server response times and un-optimized images. Learn more here.
Q: Can a site meet the recommended thresholds without using AMP?
A: Yes. You can take a look at the guidance offered on web.dev/vitals to see how you can optimize your performance against Core Web Vitals. The advantage of using AMP is that you get these web development best practices baked into the framework without added effort on your part.
Q: If my site is a Progressive Web App, does it meet the recommended thresholds?
A: Not necessarily since it would still depend on how the Progressive Web App is implemented and how real users are experiencing the page. Core Web Vitals are complementary to shipping a good PWA; it’s important that every site, whether a PWA or not, focuses on loading experience, interactivity, and layout stability. We recommend that all PWAs follow Core Web Vitals guidelines.
Q: Can a site meet the recommended thresholds if it is a Single Page Application?
A: Core Web Vitals measure the end-user experience of a particular web page and don't take into account the technologies and architectures involved in delivering that experience. Layout shifts, input delays, and contentful paints are as relevant to a Single Page Application as they are to other architectures. Different architectures may result in different friction points to address and meet the thresholds. No matter what architecture you pick, what matters is the observed user experience.
Q: My website is mobile-friendly, but my Core Web Vitals score is low on mobile. How is that possible?
A: The Page Experience signal measures aspects of how users perceive the experience of interacting with a web page. Core Web Vitals is one aspect of this along with Mobile-friendliness. These are not meant to be overlapping but additive in order to provide a holistic picture of page experience.
Q: How do I improve my LCP/CLS/FID score?
A: You can find recommendations on how to improve your Core Web Vitals metrics on web.dev/fast/. Improving metrics for your site will require web development knowledge. If you are a non-technical user, we have some suggestions in our Search Console Help Center, but you should consider contacting a professional.
Q: Why are there differences in scores between mobile and desktop?
A: At this time, using page experience as a signal for ranking will apply only to mobile Search. However, if you're measuring Core Web Vitals using your RUM tool of choice, you may find that scores differ between Mobile Web and Desktop Web. While the technology used to create the site may be similar, real users of the two versions will have different constraints such as device, viewport size, network connectivity and more.
Q: Can sessions that don't report FID be considered "bounced" sessions?
A: No, FID excludes scrolls, and there are legitimate sessions with no non-scroll input. Bounce Rate and Abandonment Rate may be defined as part of your analytics suite of choice and are not considered in the design of CWV metrics.
Q: How do Core Web Vitals account for sites whose user base comprises high-volume NBU traffic or other users with poor internet connectivity?
A: Core Web Vitals is meant to measure the quality of a user's experience on a website. The user population of each site differs and some sites — not limited to any particular region — may have significant populations of users that may be using older devices, using slower networks, and so on. In such cases sites should adapt the content to ensure that such users are still receiving a great user experience and, ideally, still meet the recommended Core Web Vitals thresholds.
Q: Do Core Web Vitals impact ranking? Starting May 2021, Core Web vitals will be included in page experience signals together with existing search signals including mobile-friendliness, safe-browsing, HTTPS-security, and intrusive interstitial guidelines. You can read more about this in our Search Central blog post.
Q: How does Google determine which pages are affected by the assessment of Page Experience and usage as a ranking signal?
A: Page experience is just one of many signals that are used to rank pages. Keep in mind that intent of the search query is still a very strong signal, so a page with a subpar page experience may still rank highly if it has great, relevant content.
Q: Is there a difference between desktop and mobile ranking?
A: At this time, using page experience as a signal for ranking will apply only to mobile Search.
Q: What can site owners expect to happen to their traffic if they don’t hit Core Web Vitals performance metrics?
A: It’s difficult to make any kind of general prediction. We may have more to share in the future when we formally announce the changes are coming into effect. Keep in mind that the content itself and its match to the kind of information a user is seeking remains a very strong signal as well.
Q: What information does Search Console provide about Core Web Vitals? What do these errors mean?
A: Search Console has released the Core Web Vitals Report, powered by Chrome UX Report data, to help site owners identify potential user experience problems. The intent is to ensure that the Core Web Vitals Report is consistent with and provides site owners visibility into the state of each of the Core Web Vitals on their site. You can find more information on what different errors mean and how to address them in the Help Center.
Q: My page is fast. Why do I see warnings on the Search Console Core Web Vitals report?
A: Different devices, network connections, geography and other factors may contribute to how a page loads and is experienced by a particular user. While some users, in certain conditions, can observe a good experience, this may not be indicative of other user's experience. Core Web Vitals look at the full body of user visits and its thresholds are assessed at the 75th percentile across the body of users. The SC CWV report helps report on this data.
Depending on how you're evaluating "Fast", remember that Core Web Vitals is looking at more than speed. For instance, Cumulative Layout Shift describes users annoyances like content moving around. Additionally, you may also use synthetic-based testing tools that try to emulate a user, but that representation may differ from your real users.
Q: When I look at Lighthouse, I see no errors. Why do I see errors on the Search Console report?
The Search Console Core Web Vitals report shows how your pages are performing based on real world usage data from the CrUX report (sometimes called “field data”). Lighthouse, on the other hand, shows data based on what is called “lab data”. Lab data is useful for debugging performance issues while developing a website, as it is collected in a controlled environment. However, it may not capture real-world bottlenecks. You can use both reports to improve the experience for your users, but the information each report provides is different.
Forum discussion at Google Webmaster Help.
