react-best-practices

Trigger phrases

Phrases that activate this skill when typed to Claude Code:

• audit this React code
• review against React best practices
• check this Next.js component

What it does

react-best-practices is a Claude Code skill that walks code against an opinionated list of 40+ React and Next.js rules. The rules cover the categories that actually move a needle in production: performance (memoization, re-renders), hooks correctness, server-vs-client component boundaries, accessibility, rendering patterns, state management, and TypeScript usage.

When activated on a chunk of React code, it produces a list of issues ordered by impact — not alphabetically, not by file, by which one will hurt your users most if you don’t fix it.

When to use it

• Reviewing a PR before merge, especially in a codebase where reviews are getting rubber-stamped
• Onboarding into an existing React/Next.js project — you want a structured second pair of eyes
• Refactoring a component that’s gone gnarly — get a prioritized list of what’s actually wrong
• Pre-launch audit of a feature

When not to reach for it:

• Non-React code (the rules don’t translate to Vue, Svelte, plain HTML)
• Tiny one-component changes — the overhead exceeds the value
• Code where the architecture is the problem, not the patterns. Audit-against-rules can’t fix architectural drift; it just lists symptoms

Install

Available in the Vercel Labs agent-skills repo. Follow the install path documented there for SKILL.md-format skills (typically copy into .claude/skills/react-best-practices/).

What a session looks like

1. You point the skill at a file or block of React/Next.js code.
2. The skill applies its 40+ rule checks and groups findings into 8 categories.
3. Output is prioritized: high-impact issues (re-render storms, missing keys on lists, hydration mismatches) first; cosmetic issues (TypeScript style preferences) last.
4. Each finding includes a brief why and the canonical fix pattern.

The discipline that makes it work: prioritization by production impact, not by lint-style alphabetical ordering. You can stop reading at the first 5 items and have addressed the actual risk.

Receipts

Where it works well:

• Catches useEffect misuse and unnecessary client components in Next.js — common cost-driving mistakes
• Surfaces accessibility regressions (missing aria-labels, keyboard traps) reliably
• The “prioritized by impact” framing produces a list you’d actually act on, not a noise wall

Where it backfires:

• On bleeding-edge React 19+ patterns or experimental features, some rules lag behind
• The skill can flag legitimate domain-specific patterns as anti-patterns; treat findings as signal, not gospel
• Doesn’t substitute for performance profiling — it catches patterns that often hurt performance, not measured performance issues

Pattern that works: run it on diffs before review, not on whole files. Diff-scoped audits get usable signal-to-noise; whole-file audits drown in legacy.

Source and attribution

From the Vercel Labs agent-skills repository. Maintained by Vercel Labs.

License: MIT. Install, adapt, redistribute with attribution.

For the canonical rule list and any updates, defer to the source repo.