# performance-profiling

A Claude skill that keeps the agent on a fixed loop: measure, find the bottleneck, change one thing, confirm the result. Useful when a page drags.

- skill · `type=skill` · Claude Code · 132 installs
- Author: davila7
- License: not stated · 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/performance-profiling
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/skills/performance-profiling

## What it does

The skill lays out an order of operations for performance work. Baseline first, then locate the bottleneck, then make a targeted change, then validate it. Skip the baseline and the agent starts guessing, which sends fixes in the wrong direction.

It ships as reference tables. Core Web Vitals targets for LCP, INP and CLS. A tool-selection table: Lighthouse for page load, a bundle analyzer for size, the Performance and Memory tabs in DevTools for runtime and heap. Symptoms map to likely causes — slow first load, heavy event handlers, janky scrolling, memory that keeps climbing. A separate anti-pattern table pushes back on micro-optimizing and on optimizing before you have data.

For an automated pass there is `scripts/lighthouse_audit.py`, run through Python. The skill's allowed tools are `Read`, `Glob`, `Grep` and `Bash`, so it inspects and measures rather than editing files — the agent applies the changes.

## Install

### Claude Code (native platform)

1. **claude-code-templates**
```bash
npx claude-code-templates@latest --skill development/performance-profiling
```

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

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

### Codex

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

### Cursor

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

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install davila7/claude-code-templates performance-profiling
```

2. **Manually: put the files in place**
- File: `.github/skills/performance-profiling/SKILL.md`

### Gemini CLI

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

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/performance-profiling/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/performance-profiling

## When to use it
- pin down what actually slows a page down
- capture a baseline before touching anything
- inspect a bundle and drop duplicate dependencies
- tell a memory leak apart from normal heap growth
- pick the right tool for a given symptom

## Example prompts
- Run a performance audit of https://example.com with `scripts/lighthouse_audit.py`
- Take a baseline for LCP and INP, then tell me what to fix first
- Look at the bundle: which dependencies are largest, and what should be split per route

## Similar
- [performance-and-web-vitals](https://affpapa.org/en/nevibecode/skills/performance-and-web-vitals.md) — skill · 975 installs
- [web-performance-audit](https://affpapa.org/en/nevibecode/skills/secondsky-web-performance-audit.md) — skill · 526 installs
- [profiling-performance](https://affpapa.org/en/nevibecode/skills/profiling-performance.md) — skill · 410 installs
- [performance-optimization](https://affpapa.org/en/nevibecode/skills/performance-optimization.md) — skill · 65200 installs
- [web-perf](https://affpapa.org/en/nevibecode/skills/cloudflare-web-perf.md) — skill · 110200 installs
- [perf-lighthouse](https://affpapa.org/en/nevibecode/skills/perf-lighthouse.md) — skill · 321 installs

## Other versions with the same name
- [performance-profiling · mengto](https://affpapa.org/en/nevibecode/skills/mengto-performance-profiling.md) — 1400 installs
- [performance-profiling · heshamfs](https://affpapa.org/en/nevibecode/skills/heshamfs-performance-profiling.md) — ★ 83

From the same set: [davila7/claude-code-templates](https://affpapa.org/en/nevibecode/by/davila7/claude-code-templates.md) — 361 cards

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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