ESLint + Prettier Setup: The Complete Developer Configuration Guide (2026)

ESLint and Prettier solve different problems: ESLint catches code quality issues (unused variables, suspicious patterns, potential bugs), while Prettier enforces consistent formatting (indentation, line length, quote style). Together, they eliminate entire categories of code review friction — reviewers focus on logic, not style. But getting them to work together without conflicts has historically been painful. This guide sets up a modern, conflict-free ESLint + Prettier configuration using ESLint's new flat config format, TypeScript support, React plugins, and automated enforcement with Husky and lint-staged pre-commit hooks. Understanding the Division of Labor Before configuring anything, understand what each tool does: Prettier: Format-only. It reformats your code into a consistent style. It is intentionally opinionated with few options. It does not catch bugs or enforce best practices. ESLint: Linting + optional formatting. By default, some ESLint rules conflict with Prettier (e.g.,