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.

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

Option 2: Manual Migration

If you prefer more control over the process, follow the Manual Migration steps by:

Installing Ultracite and Biome manually
Updating your biome.json file to extend Ultracite
Creating or updating a .vscode/settings.json file to enable the Biome extension
Enabling strictNullChecks in your tsconfig.json file (or create one if it doesn't exist)

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