Agent skill · Cloudflare

Web Performance Audit skill for Claude Code, Codex and Cursor

Diagnoses slow pages and improves Core Web Vitals and Lighthouse performance scores.

Officialname: web-perf★ 3.2k (repo)pushed 2026-10-19Apache-2.0SKILL.md on GitHubchecked 2026-11-07

What it does, in the publisher's words

Audit, diagnose, or optimize website loading and interaction performance, Core Web Vitals, and Lighthouse performance scores.

The description field of the SKILL.md. The agent reads only this at startup and decides from it when to load the full skill.

Install Web Performance Audit

The skills CLI copies the skill into the folder of each agent you pick (Claude Code, Codex, Cursor, Copilot, Gemini CLI, OpenCode, Windsurf...). Add -g for all projects. Needs Node.js 22.20+. docs

npx skills add cloudflare/skills --skill web-perf

This repo is a plugin marketplace. Inside Claude Code, add it and install the plugin that holds the skill (cloudflare), or copy only this skill into ~/.claude/skills. docs

/plugin marketplace add cloudflare/skills
/plugin install <plugin>@cloudflare

# or only this skill:
npx skills add cloudflare/skills --skill web-perf -a claude-code

Download the skill folder, zip it, then Customize > Skills > + > Create skill > Upload a skill. Code execution must be on (Settings > Capabilities). docs

git clone --depth 1 https://github.com/cloudflare/skills.git /tmp/web-perf-src
cp -r /tmp/web-perf-src/skills/web-perf ./web-perf
zip -r web-perf.zip web-perf

Codex reads skills from .agents/skills in the repo or ~/.agents/skills. Type $ in Codex to use one. docs

npx skills add cloudflare/skills --skill web-perf -a codex

gh skill (GitHub CLI 2.90+, preview) installs it for Copilot in VS Code, the CLI and the cloud agent. Copilot also reads .github/skills and ~/.copilot/skills. docs

gh skill install cloudflare/skills web-perf

Cursor reads .cursor/skills, .agents/skills and ~/.cursor/skills (and .claude/skills). It does not install loose skills from a GitHub URL, so copy it in. docs

npx skills add cloudflare/skills --skill web-perf -a cursor

Installs from the GitHub repo; --path picks this skill out of the repo. Default scope is user (all projects). docs

gemini skills install https://github.com/cloudflare/skills.git --path skills/web-perf

OpenCode reads .opencode/skills, ~/.config/opencode/skills and the Claude and .agents folders. docs

npx skills add cloudflare/skills --skill web-perf -a opencode

Windsurf (now Devin Desktop) reads .devin/skills, .windsurf/skills and ~/.codeium/windsurf/skills. docs

npx skills add cloudflare/skills --skill web-perf -a windsurf

Works with

Claude Code, Claude.ai and Claude Desktop, Codex, GitHub Copilot, Cursor, Gemini CLI, OpenCode, Windsurf and other agents that read the open Agent Skills format.

What's in the SKILL.md

17 sections

Retrieval Sources
FIRST: Verify MCP Tools Available
Key Guidelines
Quick Reference
Workflow
Phase 1: Performance Trace
Phase 2: Core Web Vitals Analysis
Phase 3: Network Analysis
Phase 4: Accessibility Snapshot
Phase 5: Codebase Analysis
Detect Framework & Bundler
Tree-Shaking & Dead Code
Unused JS/CSS
Polyfills
Compression & Minification
Output Format
Skill feedback

Bundled files

references/skill-feedback.md

Loaded only when the instructions point to them.

Facts

Skill name: web-perf
Publisher: Cloudflare (official)
Repo: cloudflare/skills
License: Apache-2.0
SKILL.md size: 1,046 words, 201 lines
Bundled files: 1, 1 docs
Repo stars: 3.2k (as of 2026-10-24)
SKILL.md checked: 2026-11-07

Pairs with the Cloudflare MCP server: the server gives the agent the tools, the skill teaches it how to use them.

More skills from cloudflare/skills

Cloudflare Agents SDK: Builds, debugs and reviews agents written with Cloudflare's agents package.
Cloudflare Platform: Helps pick Cloudflare products for an app's compute, storage, AI, networking and security needs.
Durable Objects: Writes and reviews Durable Objects code for stateful coordination on Cloudflare.
Next.js on Cloudflare: Builds or moves Next.js apps to Cloudflare Workers, comparing vinext and OpenNext.
Workers Best Practices: Production guidance for writing, configuring and reviewing Cloudflare Workers.
Wrangler CLI: Runs and troubleshoots Wrangler commands for local dev, previews, deploys and resources.

Related frontend & design skills

FAQ

What does the web-perf skill do?+

Diagnoses slow pages and improves Core Web Vitals and Lighthouse performance scores. In its own SKILL.md, Cloudflare describes it as: "Audit, diagnose, or optimize website loading and interaction performance, Core Web Vitals, and Lighthouse performance scores."

How do I install the web-perf skill?+

Run npx skills add cloudflare/skills --skill web-perf and pick your agents, or use the tab for your agent above. In Claude Code the skill ends up in ~/.claude/skills/web-perf/SKILL.md; in Codex and Cursor in .agents/skills/web-perf/.

Does Web Performance Audit work in Codex, Cursor and Copilot, or only Claude?+

It's a standard SKILL.md, so any agent that reads the Agent Skills format can use it: Claude Code, the Claude apps, Codex, GitHub Copilot, Cursor, Gemini CLI, OpenCode, Windsurf and more.

Who maintains Web Performance Audit?+

Cloudflare, the company or project behind it, in the cloudflare/skills repo on GitHub, last pushed 2026-10-19. License: Apache-2.0.

Read a skill's SKILL.md and scripts before you install it: skills aren't verified by any agent vendor. Claude skills marketplace · How to install skills · MCP servers