React Performance

A well-organized collection of 70+ React and Next.js performance rules pulled from Vercel's engineering best practices, sorted into eight priority tiers from waterfalls to advanced patterns. You'd reach for this when reviewing code, auditing Core Web Vitals regressions, or tracking down why your server components are slow. The waterfall elimination section alone (parallel Promise.all, deferred awaits, Suspense boundaries) will catch most of the low-hanging fruit in typical Next.js apps. The bundle size guidance on direct imports versus barrel files is correct and commonly ignored. It's dense enough that you'll want to activate it during refactoring sessions rather than keeping it loaded all the time, but the priority index makes it easy to focus on what actually matters for your bottleneck.

skills.sh installs: 5.9K
GitHub stars: 300.3K
last updated: Aug 21, 2026

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Install

$ npx -y skills add affaan-m/ecc --skill react-performance --agent claude-code

Installs into .claude/skills of the current project.

Files

React Performance

Performance optimization patterns for React 18/19 and Next.js, adapted from Vercel Labs react-best-practices (MIT, v1.0.0). This skill organizes rules by priority and provides decision-tree guidance for active code review and refactoring.

When to Activate

Writing or reviewing React/Next.js code for performance
Diagnosing slow page loads, slow interactions, or high CPU on the client
Auditing bundle size or Lighthouse Core Web Vitals regressions
Removing waterfalls in Server Components / API routes
Reducing client-side re-renders
Optimizing long lists, animations, or hydration
Auditing optimization choices in PRs touching app/, pages/, components/, or data layers