Keep your Next.js code correct and consistent automatically. Pick one path — the classic ESLint + Prettier pair (with eslint-config-next), or the all-in-one Biome. Each guide is complete on its own: config files, format-on-save, ignoring build output, and enforcing it in CI.
You need Node.js installed and a Next.js project to point these tools at — everything here runs in the terminal and writes a config file or two. No Next.js app yet? Scaffold one with create-next-app first.
Before you start
To practise, install VS Code and Node.js, open VS Code's integrated terminal (Ctrl+`), then scaffold and run a Next.js app with whichever package manager you use:
pnpm
pnpm create next-app@latest my-app
cd my-app
pnpm devnpm
npx create-next-app@latest my-app
cd my-app
npm run devWith the app open in VS Code, run the commands in each lesson from that same terminal. You only need one of the two paths below — they do the same job.
ESLint & Prettier
Set up ESLint and Prettier in a Next.js project — eslint-config-next with Core Web Vitals and TypeScript rules, the flat eslint.config.mjs, wiring Prettier in without conflicts, format-on-save, ignores, and enforcing it in CI.
Biome
Use Biome in a Next.js project — one fast Rust-based tool for formatting and linting. Install, biome.json, the check command, format-on-save, ignoring .next, CI, and the Next.js-specific trade-off versus eslint-config-next.