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.

Quick Start

npx ultracite init

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

Oxlint TypeScript Configs

If you're using oxlint.config.ts, import the typed presets instead of the raw JSON files:

import { defineConfig } from "oxlint";

import { core, next, react } from "ultracite/oxlint";

export default defineConfig({
  extends: [core, react, next],
});

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.

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