Web Performance Audit

This is a structured Chrome DevTools performance audit that walks you through the full workflow: trace capture, Core Web Vitals analysis, network waterfall inspection, and accessibility snapshots. It's opinionated in useful ways, telling you to skip non-issues like 0ms render-blocking resources and quantify impact before recommending changes. The Phase 5 codebase analysis is surprisingly thorough, detecting framework configs and checking for tree-shaking, polyfills, and compression settings. Best for methodical audits where you want a checklist-driven approach rather than ad-hoc profiling. Requires the chrome-devtools MCP server, which it checks upfront. The output format pushes you toward specific, actionable recommendations with estimated impact ratings.

skills.sh installs: 202
GitHub stars: 824
last updated: Aug 21, 2026

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Install

$ npx -y skills add warpdotdev/oz-skills --skill web-performance-audit --agent claude-code

Installs into .claude/skills of the current project.

Files

Web Performance Audit

Audit web page performance using Chrome DevTools MCP tools. This skill focuses on Core Web Vitals, network optimization, and high-level accessibility gaps.

FIRST: Verify MCP Tools Available

Run this before starting. Try calling navigate_page or performance_start_trace. If unavailable, STOP—the chrome-devtools MCP server isn't configured.

Ask the user to add this to their MCP config:

"chrome-devtools": {
  "type": "local",
  "command": ["npx", "-y", "chrome-devtools-mcp@latest"]
}

Key Guidelines

Be assertive: Verify claims by checking network requests, DOM, or codebase—then state findings definitively.
Verify before recommending: Confirm something is unused before suggesting removal.
Quantify impact: Use estimated savings from insights. Don't prioritize changes with 0ms impact.
Skip non-issues: If render-blocking resources have 0ms estimated impact, note but don't recommend action.
Be specific: Say "compress hero.png (450KB) to WebP" not "optimize images".
Prioritize ruthlessly: A site with 200ms LCP and 0 CLS is already excellent—say so.