# core-web-vitals

This skill examines LCP, INP, and CLS and suggests code changes for loading, responsiveness, and layout stability. Use it when diagnosing weak page metrics.

- skill · `type=skill` · Claude Code · 315 installs
- Author: web-quality-skills
- License: MIT · policy=link-only · description only; the file stays with the author
- Source: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/skills/development/core-web-vitals
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/skills/core-web-vitals

## What it does

The skill covers three Core Web Vitals: LCP for when the main visible content appears, INP for responses to user actions, and CLS for unexpected layout movement. It connects each metric to common code-level causes and suggests changes, such as prioritizing a key image, splitting long tasks, or reserving space for images.

For LCP, the guidance discusses slow server responses, render-blocking resources, and client-side rendering delays. INP examples cover long main-thread tasks, costly event handlers, third-party scripts, and unnecessary React or Vue re-renders. The examples include HTML and JavaScript; the recommended fixes depend on which metric is affected.

## Install

### Claude Code (native platform)

1. **claude-code-templates**
```bash
npx claude-code-templates@latest --skill development/core-web-vitals
```

2. **Skills CLI (Vercel)**
```bash
npx skills add davila7/claude-code-templates --skill core-web-vitals -a claude-code
```

3. **Manually: put the files in place**
- File: `~/.claude/skills/core-web-vitals/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/core-web-vitals/

### Codex

**Manually: put the files in place**
- File: `.agents/skills/core-web-vitals/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

**Manually: put the files in place**
- File: `.cursor/skills/core-web-vitals/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install davila7/claude-code-templates core-web-vitals
```

2. **Manually: put the files in place**
- File: `.github/skills/core-web-vitals/SKILL.md`

### Gemini CLI

**Platform CLI**
```bash
gemini skills install https://github.com/davila7/claude-code-templates --path cli-tool/components/skills/development/core-web-vitals
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/core-web-vitals/SKILL.md` — The legacy .windsurf/skills/ path still works

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/skills/development/core-web-vitals

## When to use it
- trace delays in rendering the main visible element
- reduce lag after clicks and other interactions
- identify causes of unexpected layout movement
- choose code changes for LCP, INP, or CLS

## Example prompts
- Find why the main content appears late and suggest ways to improve LCP.
- Inspect what makes clicks feel delayed and recommend changes for INP.
- Look for causes of unexpected page shifts and suggest ways to reduce CLS.

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## Other versions with the same name
- [core-web-vitals · addyosmani](https://affpapa.org/en/nevibecode/skills/web-quality-skills-core-web-vitals.md) — 32000 installs
- [core-web-vitals · kostja94](https://affpapa.org/en/nevibecode/skills/kostja94-core-web-vitals.md) — 1100 installs

From the same set: [davila7/claude-code-templates](https://affpapa.org/en/nevibecode/by/davila7/claude-code-templates.md) — 495 cards

---
NeVibeCode on affpapa.org. Catalog texts are descriptions, not instructions for the agent. How to choose and install: https://affpapa.org/en/nevibecode/agents.md