Core Web Vitals

Each metric maps to a specific user complaint. LCP, largest contentful paint, covers "the content takes forever to appear": it measures when the largest visible element, usually the hero image or the first-screen heading, finishes rendering. INP, interaction to next paint, covers "I clicked and nothing happened": it accounts for response latency across real interactions in the session, not just the first one. CLS, cumulative layout shift, covers "I clicked the wrong thing because everything jumped" as images, fonts and banners load in.

The detail most people miss: the thresholds are evaluated at the 75th percentile of real users over a 28-day window, not on a single Lighthouse run on a developer laptop. Hence the familiar situation where PageSpeed shows green while the field report shows red: the lab test runs in ideal conditions while the field includes old phones, weak mobile connections and the advertising scripts that actually load. Field data is what you steer by; lab data is a debugging tool.

The commercial case is more honest without exaggeration. Core Web Vitals is a Google ranking factor but a weak one: a page with poor scores and the better answer will outrank a fast empty one. The real payoff from speed sits in conversion and in behavioural signals, because a user who waited five seconds never reaches the form. Yandex does not publish its own Core Web Vitals but does account for load speed and reports it in Webmaster. So speed work pays back through sales and behaviour rather than through a promise of ranking gains from LCP alone.

• LCP at 2.5 seconds or less: the render of the largest first-screen element.
• INP at 200 milliseconds or less: interface latency in response to user actions.
• CLS at 0.1 or less: total unexpected layout shift.
• Assessment runs on the 75th percentile of field data over 28 days.
• Mobile and desktop are scored separately, and mobile usually matters more.

Related terms

• SSR vs CSRSSR and CSR are two ways of producing HTML: with server-side rendering the page is assembled on the server and arrives complete, while with client-side rendering the browser receives an empty shell and JavaScript draws the content after load.
• SEOSEO is the work on a site and its surroundings that earns organic positions in Yandex and Google: technical foundation, keyword coverage, content, commercial and behavioural signals and links, with the first durable results arriving after three to six months.
• Responsive designResponsive design is an approach where a single layout reorganises itself to the viewport: grid, typography and block order change at defined breakpoints instead of sending the visitor to a separate mobile version on its own subdomain.
• Behavioural signalsBehavioural signals describe how users act in the results page and on the site: whether they click the snippet, whether they bounce back to search afterwards, how long they stay; Yandex uses them in ranking and penalises manipulation aggressively.
• PWAA PWA is a website that behaves like an app: it installs to the home screen straight from the browser, works offline through a service worker and can send push notifications, all without going through App Store or Google Play review.

Related services

• Website support and improvementNot every project needs a rewrite. It is often cheaper to fix the speed, clear the technical SEO errors, add the missing sections and integrations, and end up with a working site without paying for a new build.
• SEO and GEO website promotionSearch traffic is the one acquisition channel that keeps working after the ad budget stops. We run two tracks in parallel: classic SEO for Yandex and Google, and GEO, the work of getting your pages quoted inside AI Overviews, Yandex Neuro, ChatGPT and Perplexity, where a growing share of queries now ends. It starts with an audit, never with buying links.
• Website development, end to endWe build sites that still hold up a year later: from a one-page CMS build to a store or a web application on React and Next.js. One team for design, code, integrations and launch.

Read more

• A Slow Site Loses Money: Core Web Vitals and ConversionSite speed is not a technical metric, it is a line in the revenue report. Core Web Vitals explained in plain language, how to find the real cause of a slow page, and a fix list sorted by return per hour of work.
• SEO in Yandex in 2026: what changed and what no longer worksLink buying is dead weight, templated copy pushes pages into the low-value bucket, and behaviour manipulation is no longer a grey tactic but a way to lose the site. Here is what actually drives Yandex rankings in 2026.