사용 방법
- 설치 명령을 복사하고 자신의 에이전트 환경에 설치하기 전에 소스 패키지를 확인하세요.
- 필요한 도구, 인증 정보, 지원 환경은 원본 문서에서 확인하세요.
- 입력과 원하는 산출물을 설명하고 출처와 결과를 대조하세요.
npx skills add https://github.com/kostja94/marketing-skills --skill core-web-vitals시작 전 확인
- 설치에는 모델 구독, API 한도, 파일 접근 권한이 포함되지 않습니다.
- 별점 수와 설치 수는 활동 지표이며 독립적인 품질·보안 검증이 아닙니다.
원본 저장소의 제목, 예시, 코드, 표, 링크, 이미지를 유지해 표시합니다.
SEO Technical: Core Web Vitals
Guides optimization of Core Web Vitals (CWV)—Google's user experience metrics that affect search ranking. CWV are confirmed ranking factors for mobile and desktop.
When invoking: On first use, if helpful, open with 1–2 sentences on what this skill covers and why it matters, then provide the main output. On subsequent use or when the user asks to skip, go directly to the main output.
Scope (Technical SEO)
- LCP (Largest Contentful Paint): Loading performance; time to render largest content element
- INP (Interaction to Next Paint): Responsiveness; replaced FID on March 12, 2024
- CLS (Cumulative Layout Shift): Visual stability; unexpected layout shifts
Target Thresholds (75th percentile, field data)
| Metric | Target | Good | Needs Improvement | Poor |
|---|---|---|---|---|
| LCP | ≤2.5s | ≤2.5s | 2.5–4.0s | >4.0s |
| INP | ≤200ms | ≤200ms | 200–500ms | >500ms |
| CLS | <0.1 | ≤0.1 | 0.1–0.25 | >0.25 |
Source: Google Page Experience
Initial Assessment
Project context: Read root contextus.md when present and load only the modules relevant to this task. Without Contextus, use available project material or user-provided facts and ask for missing information; do not create a parallel context system.
Identify:
- Tools: GSC Core Web Vitals report, PageSpeed Insights, Chrome DevTools
- Metrics: Which metric is failing (LCP, INP, CLS)
- Page type: Hero, article, product, list—LCP candidate differs
LCP Optimization
LCP measures the time until the largest content element (image, video, or text block) is visible.
| Cause | Fix |
|---|---|
| Slow server response | Reduce TTFB; use CDN; optimize server |
| Render-blocking resources | Defer non-critical CSS/JS; inline critical CSS |
| Large images | WebP/AVIF; compress; width/height to prevent CLS; see image-optimization |
| Client-side rendering | SSR/SSG for above-fold content; see rendering-strategies |
| Third-party scripts | Load async; defer non-critical |
LCP candidates: Hero image, large text block, video poster. Ensure above-fold images use loading="eager" (default); never lazy-load LCP.
INP Optimization
INP measures responsiveness—time from user interaction to next paint. Replaced FID on March 12, 2024.
| Cause | Fix |
|---|---|
| Long-running JS | Break tasks >50ms; use requestIdleCallback; Web Workers |
| Heavy event handlers | Debounce/throttle; defer non-critical work |
| Main thread blocking | Reduce third-party scripts; defer non-critical JS |
| Layout thrashing | Batch DOM reads/writes; avoid forced reflows |
CLS Optimization
CLS measures unexpected layout shifts.
| Cause | Fix |
|---|---|
| Images without dimensions | Always set width and height attributes |
| Dynamic content | Reserve space for ads, embeds; use min-height |
| Web fonts | font-display: optional or swap; preload critical fonts |
| Animations | Use transform instead of top/left/width |
Reserve space: For images, ads, embeds—define dimensions before load. Avoid inserting content above existing content without reserved space.
Tools & Monitoring
| Tool | Use |
|---|---|
| GSC | Core Web Vitals report; URL grouping; field data |
| PageSpeed Insights | Lab + field data; mobile + desktop |
| Chrome DevTools | Performance panel; LCP element; layout shift overlay |
Output Format
- Current state: Which metrics fail (LCP, INP, CLS)
- Prioritized fixes: By impact
- References: Web Vitals, Page Experience
Related Skills
- image-optimization: LCP image optimization; WebP; lazy loading (below-fold only)
- google-search-console: CWV report; field data monitoring
- mobile-friendly: Mobile-first indexing; mobile CWV targets
- rendering-strategies: SSR/SSG for LCP; content in initial HTML
- site-crawlability: Redirect chains waste crawl; fix for performance



