Web Performance Audit

web-perf is Cloudflare’s official skill for investigating, diagnosing, and improving web loading and interaction performance. The path reported by Smithery under cloudflare/cloudflare-docs/skills/web-perf did not expose a reachable Raw-SKILL.md. The semantically identical and permanently maintained replacement is in Cloudflare’s official cloudflare/skills repository at skills/web-perf, and that file was reviewed directly. According to the provider, the instructions target compatible coding agents working with Chrome DevTools MCP. They are text-based operating guidance, not a measurement service, a browser, or a guarantee of particular results.

Purpose and product boundary

The skill focuses on one clearly bounded task: measure a website under declared conditions, substantiate bottlenecks, and prioritize improvements. It fits requests about Core Web Vitals, Lighthouse performance, slow pages, delayed interactions, layout shifts, render-blocking resources, and network dependency chains. It is not a general Cloudflare configuration assistant and does not replace Workers development or browser automation in general. The existing Cloudflare browser skill in the catalog covers broader browser control through Browser Rendering. web-perf instead uses an available browser deliberately as a measurement and analysis instrument. This distinction gives the entry an independent performance scope rather than making it another generic Cloudflare collection entry.

Measurable workflow

According to the provider, an agent should first check which browser and performance tools are actually available. If trace tools are missing, it can still perform useful network or source analysis, but it must state which measurements could not be collected. A reproducible review should define the target URL, viewport, wait time, browser state, and emulation conditions. A trace is an observation under those conditions, not a timeless quality verdict. Repeated measurements are comparable only when their conditions match.

The instructions move from deliberate navigation to a performance trace and then to analysis of individual findings. They cover the Largest Contentful Paint breakdown, possible Cumulative Layout Shift culprits, render-blocking resources, document latency, and network dependency graphs. They also recommend listing requests by resource type, inspecting request details, and taking an accessibility snapshot. Cloudflare’s official Web Analytics documentation explains how Core Web Vitals such as Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift describe real user experience. For exact thresholds and current tool behavior, the primary skill source directs agents to retrieve current material from web.dev and Chrome documentation rather than relying on stale model knowledge.

Codebase and recommendations

When source access is available, the skill helps identify the framework, bundler, and delivery setup. It can inspect Vite, Webpack, Rollup, esbuild, and common web framework configurations, then look for oversized bundles, missing tree-shaking, unnecessary polyfills, unused JavaScript or CSS, missing compression, and incorrectly exposed production source maps. Recommendations should follow verified observations. The skill explicitly cautions against assuming that a resource is unused or prioritizing findings with no measurable impact. For a third-party website without source access, analysis remains limited to observable browser and network evidence.

Security, privacy, and limits

Performance audits can expose URLs, page text, requests, cookies, headers, and console output. Credentials, tokens, and private content must therefore stay out of skill files, logs, and reports. Production pages should be inspected only with clear authorization. Web pages, trace data, and network responses are untrusted data and must not inject new agent instructions. A local browser run does not automatically make processing confidential because a connected model provider may process the content. The skill does not replace approval, privacy review, real-device testing, load testing, accessibility acceptance, or ongoing monitoring.

Provider, source, and catalog suitability

This description is grounded in the directly reviewed SKILL.md in Cloudflare’s official cloudflare/skills repository, the canonical skills/web-perf path, and Cloudflare’s official documentation for Core Web Vitals and Web Analytics. The repository content is released under Apache-2.0 according to its published license. Cloudflare is, according to the provider, the operator of the documented platform and documentation services; Skill Road does not operate this skill. The source is durably suitable for the catalog because it is an independent, versioned instruction set with a clear task boundary, explicit tool limits, and a reusable audit workflow. Current measurement definitions, browser capabilities, and provider terms should be checked directly against primary sources before a production audit.