Speed is hygiene
A slow, janky page can drag your rankings down. Once Core Web Vitals are at “good,” a faster page rarely moves them, because quality, expertise and trust do the heavy lifting.
The framing is ours. It borrows Frederick Herzberg’s “hygiene factors” from management theory: things that hurt when they’re missing but add little once they’re adequate. A clean office won’t motivate anyone, but a dirty one will drive people out.
What to do
Reach the “good” thresholds, especially on mobile, and fix real problems like slow LCP, layout shift and sluggish interactions. Past that point, chasing a higher Lighthouse score won’t beat stronger content or authority.
The “good” thresholds
Google judges Core Web Vitals on real-user data at the 75th percentile of page loads. A page passes only when all three are good.
| Metric | Good | Needs improvement | Poor |
|---|---|---|---|
| Largest Contentful Paint: how long until the biggest thing on screen shows up. (loading) | ≤ 2.5 s | ≤ 4.0 s | > 4.0 s |
| Interaction to Next Paint: how fast the page reacts when someone taps or clicks. (responsiveness) | ≤ 200 ms | ≤ 500 ms | > 500 ms |
| Cumulative Layout Shift: how much the page jumps around while it loads. (visual stability) | ≤ 0.1 | ≤ 0.25 | > 0.25 |
Lab tests can’t measure INP, so we show Total Blocking Time as a stand-in, labeled “proxy.” The 0-100 Lighthouse score has its own colors and isn’t the same thing as “good.”
How to read these scores
- Lab, not field. Our tests run on simulated hardware. Google ranks on field data from real Chrome users, so when the two disagree, trust the field data.
- Scores swing between runs. That’s why we show medians and how many runs (n) each one is based on.
- Compare a page with its own past. Not with competitors, and not across engines that use different machines and settings.
- The score is a curve. Going from 90 to 100 is far harder than going from 50 to 60, and new Lighthouse versions can shift it with no change to your site.
- Category scores are checklists. A 100 in Accessibility doesn’t mean the site is accessible, because most WCAG checks need a person.
Does speed affect rankings?
Yes, but only a little. Speed mostly acts as a tiebreaker between otherwise comparable pages.
- Google’s John Mueller has said Core Web Vitals aren’t a big ranking factor (Stan Ventures).
- Mike King’s 2021 analysis found domains passing all three gained about 1% in visibility and domains failing one were 3.7% less visible, though the net change for slower domains was flat (deck). The 2024 leak suggests click data can also hurt slow sites indirectly (Search Engine Land, SEO Week 2025).
- Lily Ray argues that fixing Core Web Vitals won’t fix trust or quality (BuzzStream).