Migrate from Biome

If you're already using Biome and want to switch to Ultracite's preconfigured setup, this guide will help you migrate while preserving your existing configuration.

Why Migrate to Ultracite?

• Zero Configuration: Ultracite provides a highly configured preset of rules
• Editor Integration: Built-in support for AI-powered editors (Cursor, Windsurf, GitHub Copilot)
• Consistent Workflow: Standardized setup across projects and teams
• Additional Tooling: Optional Git hooks, lint-staged integration
• Maintained Rules: Regular updates with new best practices

Before You Start

Make sure you have:

• An existing project using Biome
• Node.js v14.18+ (Node 18+ recommended)
• A biome.json or biome.jsonc file

Migration Options

Option 1: Quick Migration (Recommended)

The fastest way is to run the automatic setup script.

npx ultracite init

When prompted, select Biome as your linting provider. This will:

• Install Ultracite as a dependency
• Merge your existing biome.json / biome.jsonc with Ultracite's preset
• Merge your existing .vscode/settings.json with Ultracite's preset
• Enable strictNullChecks in your tsconfig.json file (or create one if it doesn't exist)
• Preserve your custom rules and settings
• Set up editor integrations

Following the upgrade, you may want to review your biome.json / biome.jsonc file to remove any overrides that are now handled by Ultracite's preset.

Option 2: Manual Migration

If you prefer more control over the process, update your biome.jsonc to extend Ultracite:

{
  "extends": ["ultracite/biome/core"]
}

After the migration, restart your editor to ensure the new configuration is applied.