---
id: wiki-2026-0508-page-experience-algorithm
title: Page Experience Algorithm
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [Google Page Experience, Core Web Vitals ranking, INP]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [seo, web-performance, core-web-vitals, google]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: N/A
  framework: Google Search Ranking
---

# Page Experience Algorithm

## 매 한 줄
> **"매 Google 의 ranking signal 으로서 의 매 user perceived UX metric"**. 매 2021 Page Experience update 매 mobile 적용, 매 2022 desktop 확장, 매 2024-03 매 FID → INP 교체. 매 2026 의 매 core signal: LCP / INP / CLS + HTTPS / mobile-friendly / no-intrusive-interstitial.

## 매 핵심

### 매 Core Web Vitals (2026)
- **LCP (Largest Contentful Paint)**: 매 viewport 의 매 largest element render 시간. **Good < 2.5s**.
- **INP (Interaction to Next Paint)**: 매 모든 interaction 의 매 max latency (75th percentile). **Good < 200ms**.
- **CLS (Cumulative Layout Shift)**: 매 unexpected layout shift 누적 score. **Good < 0.1**.

### 매 추가 signal
- HTTPS 적용.
- Mobile-friendly (responsive).
- No intrusive interstitial (popup ad coverage).
- (deprecated 2024-03) Safe Browsing — 매 separate signal.

### 매 측정 source
- **CrUX (Chrome UX Report)**: 매 28-day rolling RUM data, 매 actual ranking signal.
- **PageSpeed Insights**: 매 lab + field 결합 view.
- **Search Console > Core Web Vitals report**.
- **web-vitals.js**: 매 self-RUM library.

### 매 응용
1. SEO ranking 향상.
2. Conversion rate 개선 (slow → bounce).
3. AdSense ad serving quality.
4. Discover feed 노출 자격.

## 💻 패턴

### 1. web-vitals.js 측정
```ts
import { onLCP, onINP, onCLS } from 'web-vitals';

onLCP((metric) => sendToAnalytics('LCP', metric));
onINP((metric) => sendToAnalytics('INP', metric));
onCLS((metric) => sendToAnalytics('CLS', metric));

function sendToAnalytics(name: string, metric: any) {
  navigator.sendBeacon('/rum', JSON.stringify({
    name, value: metric.value, id: metric.id, rating: metric.rating
  }));
}
```

### 2. LCP 최적화 — preload hero image
```html
<link rel="preload" as="image"
      href="/hero.webp"
      fetchpriority="high"
      imagesrcset="/hero-800.webp 800w, /hero-1600.webp 1600w"
      imagesizes="100vw">
```

### 3. INP 최적화 — long task break
```ts
async function processLargeList(items: Item[]) {
  for (let i = 0; i < items.length; i++) {
    process(items[i]);
    if (i % 50 === 0) {
      await scheduler.yield();  // 매 2026 Scheduler API
    }
  }
}
```

### 4. CLS 방지 — explicit dimensions
```html
<img src="/photo.webp" width="800" height="600" alt="...">
<iframe src="..." width="560" height="315"></iframe>

<!-- font swap reserve space -->
<style>
  @font-face {
    font-family: "Inter";
    src: url(/inter.woff2) format("woff2");
    size-adjust: 100%;
    ascent-override: 90%;
    font-display: swap;
  }
</style>
```

### 5. Defer non-critical JS
```html
<script src="/analytics.js" defer></script>
<script type="module" src="/app.js"></script>
<script src="/legacy.js" nomodule defer></script>
```

### 6. Resource hints
```html
<link rel="preconnect" href="https://cdn.example.com" crossorigin>
<link rel="dns-prefetch" href="https://api.example.com">
<link rel="modulepreload" href="/critical-module.js">
```

### 7. CrUX API query (BigQuery)
```sql
SELECT
  origin,
  largest_contentful_paint.histogram.density AS lcp_density,
  interaction_to_next_paint.histogram.density AS inp_density
FROM `chrome-ux-report.materialized.country_summary`
WHERE country_code = 'kr'
  AND yyyymm = 202604
  AND device = 'phone'
  AND origin = 'https://example.com';
```

## 매 결정 기준
| 상황 | Priority |
|---|---|
| LCP > 4s | Hero image preload + fetchpriority=high (매 first) |
| INP > 500ms | React 18+ concurrent + scheduler.yield() (매 2번째) |
| CLS > 0.25 | Image dimensions + font swap stabilization (매 quick win) |
| All green but slow ranking | Beyond CWV — content quality matters |
| Mobile-only fail | Test 매 mobile network throttle (Slow 4G) |

**기본값**: web-vitals.js + Lighthouse CI + CrUX field monitoring 의 매 weekly review.

## 🔗 Graph
- 부모: [[SEO]] · [[Web Performance]]
- 변형: [[Lighthouse]]
- 응용: [[Core Web Vitals Optimization (INP, LCP 개선)|Core Web Vitals]]
- Adjacent: [[Lighthouse CI]] · [[PageSpeed Insights]]

## 🤖 LLM 활용
**언제**: 매 SEO-driven traffic 매 critical (e-commerce, news, blog). 매 ranking 매 stagnant + 매 lab metric 양호 한 경우.
**언제 X**: 매 internal tool / B2B SaaS (organic search 매 minor). 매 ranking 의 매 dominant signal 의 X — 매 content 매 first.

## ❌ 안티패턴
- **Lab metric 만 monitor**: 매 PageSpeed score 100 + 매 field CrUX poor — 매 real users 의 perspective 누락.
- **75th percentile 무시**: 매 mean / median 매 deceiving — 매 long tail 매 ranking 결정.
- **INP 의 무시**: 매 2024-03 부터 매 FID 대체 — 매 legacy site 매 INP regression 매 routine.
- **CLS shift container 매 transform 으로 회피**: 매 actual layout 매 jarring — 매 reserved space 가 매 정답.
- **Preload 의 abuse**: 매 모든 image preload → 매 critical asset 매 starve.

## 🧪 검증 / 중복
- Verified (web.dev/vitals 2026-05, Google Search Central 공식 docs, CrUX dataset).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — INP-replaces-FID + 2026 Scheduler API yield pattern |
