Biome to Oxc Migration

Migrate from Biome to oxlint (linting) + oxfmt (formatting) with Prettier for unsupported file types.

File Type Strategy

File Type	Lint	Format
`.ts`, `.tsx`, `.js`, `.jsx`	oxlint	oxfmt
`.json`, `.jsonc`, `.css`	-	oxfmt
`.md`, `.mdx`, `.astro`, `.yaml`, `.yml`	-	Prettier

Migration Checklist

•Remove Biome packages - @biomejs/biome, ultracite, or similar presets
•Add new packages - oxlint, oxfmt, prettier, framework-specific prettier plugins if needed
•Delete biome.json or biome.jsonc
•Create .oxlintrc.json
•Create .prettierrc.json and .prettierignore
•Update build scripts - Replace biome commands with oxlint/oxfmt/prettier
•Update VSCode settings - Switch formatter to oxc.oxc-vscode
•Run format and lint - Verify everything works

Configuration Templates

.oxlintrc.json

json

{
  "$schema": "./node_modules/oxlint/configuration_schema.json",
  "plugins": ["typescript", "import", "unicorn", "oxc", "jsdoc", "promise", "node"],
  "rules": {}
}

Available plugins: eslint, react, unicorn, typescript, oxc, import, jsdoc, jest, vitest, jsx-a11y, nextjs, react-perf, promise, node, vue

Enable plugins relevant to your project. For library projects, exclude framework-specific plugins (react, vue, nextjs, jest, vitest).

.prettierrc.json

json

{
  "printWidth": 120,
  "plugins": ["prettier-plugin-astro"]
}

Add plugins as needed: prettier-plugin-astro, prettier-plugin-svelte, prettier-plugin-tailwindcss

.prettierignore

code

dist/
node_modules/
**/*.ts
**/*.tsx
**/*.js
**/*.jsx
**/*.json
**/*.css

Exclude files handled by oxfmt.

VSCode Settings

json

{
  "editor.defaultFormatter": "esbenp.prettier-vscode",
  "[javascript][typescript][javascriptreact][typescriptreact][json][jsonc][css]": {
    "editor.defaultFormatter": "oxc.oxc-vscode"
  },
  "editor.codeActionsOnSave": {
    "source.fixAll.oxc": "always"
  }
}

Rule Migration

Common Biome to oxlint rule mappings:

Biome Rule	oxlint Equivalent
`noBarrelFile`	`no-barrel-file`
`useConsistentTypeDefinitions`	Not directly available
`noUnusedVariables`	`no-unused-vars`
`noConsole`	`no-console`

oxlint uses ESLint-compatible rule names with kebab-case.

CLI Commands

bash

# Lint with auto-fix
oxlint --fix

# Format with oxfmt (use .gitignore for ignoring)
oxfmt --write --ignore-path=.gitignore .

# Format remaining files with Prettier
prettier --write --no-error-on-unmatched-pattern "**/*.{md,mdx,astro,yaml,yml}"

Note: oxfmt reads .prettierignore by default. Use --ignore-path=.gitignore to use gitignore instead.