Ultracite

A production-grade, zero-configuration preset for ESLint, Biome, and Oxlint.

Ultracite is designed to help you and your AI models write consistent and type-safe code without the hassle of configuration. Choose your preferred toolchain and get started in seconds.

<div> <img src="https://img.shields.io/npm/dy/ultracite" alt="" /> <img src="https://img.shields.io/npm/v/ultracite" alt="" /> <img src="https://img.shields.io/github/license/haydenbleasel/ultracite" alt="" /> </div>

Quick Start

npx ultracite init

The interactive setup will guide you through selecting your formatter/linter, framework, editor, and AI agents.

Supported Tools

• Biome — All-in-one formatting and linting
• ESLint + Prettier + Stylelint — Most mature ecosystem with the largest plugin support
• Oxlint + Oxfmt — 50-100x faster than ESLint, part of the Oxc ecosystem

Key Features

⚡ Subsecond Performance

Built on Rust-based tools for instant code analysis. On-save checks feel seamless without interrupting your workflow.

🎯 Zero-Config by Design

Hundreds of preconfigured rules optimized for JavaScript and TypeScript projects. Customize when needed, but it works perfectly out of the box.

🤖 AI-Ready

Generate rules for 20+ AI agents including Claude Code, GitHub Copilot, Cursor, Gemini, and more. Ensures consistent code style across all team members and AI models.

🏗️ Monorepo Ready

Unified toolchain configuration across all packages and apps, eliminating duplicate config files while maintaining consistency.

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Read the docs for detailed setup instructions, configuration options, and examples.