Jest vs Vitest
2026年、最適なツールを選ぶための詳細比較
🏆 クイック判定
勝者: Vitest
Vitest is the recommended choice for new projects, especially those using Vite. It's faster, has native ESM/TypeScript support, and offers a Jest-compatible API for easy migration. Jest remains solid for existing projects.
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📊 Visual Comparison
総合スコア比較
カテゴリー別分析
Jest ハイライト
- ✅ Industry standard with massive adoption
- ✅ Zero-config for most projects
- 💰 Free
Vitest ハイライト
- ✅ Blazing fast execution with Vite
- ✅ Native ESM and TypeScript support
- 💰 Free
機能比較
| Feature | Jest | Vitest |
|---|---|---|
| Configuration | Zero-config or jest.config | vitest.config or vite.config |
| Watch Mode | ✓ | Smart with HMR |
| Mocking | Built-in jest.mock() | Built-in vi.mock() |
| Code Coverage | Built-in (Istanbul) | Built-in (v8 or Istanbul) |
| Snapshot Testing | Built-in | Built-in |
| Parallel Execution | Worker-based | Worker threads |
| TypeScript | Via ts-jest or @swc/jest | Native (via Vite) |
| ESM Support | Experimental | Native |
| Browser Testing | Via jsdom | Vitest Browser Mode |
| IDE Integration | Excellent | Good (VS Code extension) |
Jestとは？
Jest is the most popular JavaScript testing framework, created by Facebook. It provides a zero-config testing experience with built-in mocking, code coverage, and snapshot testing.
✅メリット
- •Industry standard with massive adoption
- •Zero-config for most projects
- •Built-in mocking and assertions
- •Snapshot testing
- •Great IDE integration
- •Huge community and ecosystem
❌デメリット
- •Slow for large test suites
- •ESM support still evolving
- •Heavy dependency footprint
- •Configuration can become complex
- •Watch mode less responsive than Vitest
- •Not optimized for Vite/modern tooling
Vitestとは？
Vitest is a blazing-fast unit testing framework powered by Vite. It offers Jest-compatible APIs with native ESM support, TypeScript integration, and significantly faster execution.
✅メリット
- •Blazing fast execution with Vite
- •Native ESM and TypeScript support
- •Jest-compatible API (easy migration)
- •Excellent watch mode with HMR
- •Built-in UI for test visualization
- •First-class Vite integration
❌デメリット
- •Smaller community than Jest
- •Newer with less battle-testing
- •Some Jest plugins not compatible
- •Best experience requires Vite
- •Less IDE integration than Jest
- •Ecosystem still growing
料金比較
📊詳細分析: Jest vs Vitest
JestとVitestのどちらを選ぶかは、両ツールが現代のワークフローに魅力的な機能を提供しているため、難しい選択となることがあります。この包括的な比較では、機能や価格から実際のユースケースまで、あらゆる側面を分析し、情報に基づいた意思決定をお手伝いします。
Jest
Jest is the most popular JavaScript testing framework, created by Facebook. It provides a zero-config testing experience with built-in mocking, code coverage, and snapshot testing.
Vitest
Vitest is a blazing-fast unit testing framework powered by Vite. It offers Jest-compatible APIs with native ESM support, TypeScript integration, and significantly faster execution.
🎯最適なユースケース
Jestを選ぶべき時
- ✓チーム向け:
Industry standard with massive adoption
- ✓中小企業向け:
Zero-config for most projects
- ✓エンタープライズ向け:
Built-in mocking and assertions
Vitestを選ぶべき時
- ✓個人向け:
Blazing fast execution with Vite
- ✓中小企業向け:
Native ESM and TypeScript support
- ✓チーム向け:
Jest-compatible API (easy migration)
🔍機能の詳細分析
Configuration
Watch Mode
Mocking
Code Coverage
Snapshot Testing
Parallel Execution
💰価格分析
Jest
Open source
✅ 無料プランありVitest
Open source
✅ 無料プランあり💡 Pro Tip
両ツールは無料トライアルまたは無料プランを提供しています。有料プランに加入する前に、実際のワークフローで両方をテストすることをお勧めします。
🏆おすすめ
広範な分析とテストの結果、私たちの見解は次のとおりです：JestとVitestはどちらも生産性を大幅に向上させる優れたツールです。最適な選択は、あなたの具体的なニーズ、ワークフロー、優先事項によって異なります。
Choose Jest if:
You have a large existing Jest test suite, need maximum ecosystem compatibility, or your project doesn't use Vite.
Choose Vitest if:
You're starting a new project, use Vite, want faster test execution, or need native ESM and TypeScript support.
よくある質問
Very easy. Vitest is designed to be Jest-compatible. Most tests work with minimal changes — mainly replacing 'jest' with 'vi' in mock calls.
最終結論：どちらを選ぶべき？
✨ Jestを選ぶべき場合
You have a large existing Jest test suite, need maximum ecosystem compatibility, or your project doesn't use Vite.
✨ Vitestを選ぶべき場合
You're starting a new project, use Vite, want faster test execution, or need native ESM and TypeScript support.