Express is a mature Node.js web framework with the largest ecosystem and easiest learning curve, while FastAPI is a modern Python framework offering 3.5x faster performance, automatic API documentation, and built-in async support. Choose Express for maximum flexibility and community libraries; choose FastAPI for speed and developer productivity.
Express vs FastAPI — Side-by-side comparison on A Versus B
Mature, minimalist Node.js web framework with largest middleware ecosystem and production adoption.
Modern async-first Python framework for building high-performance APIs
Language & Runtime. Requests Per Second (benchmark). Time to First API (minutes). NPM/PyPI Packages Available. Automatic API Documentation. Data Validation. GitHub Stars (2026)
Choose Express if you need maximum ecosystem flexibility, have JavaScript expertise, or require extensive middleware libraries for complex use cases like real-time applications. Choose FastAPI if performance is critical, you want rapid API development with minimal boilerplate, automatic documentation, or prefer Python's readability and scientific computing libraries.
Express.js: ~40ms | FastAPI: 150ms (average)
Express.js: No (requires middleware) | FastAPI: N/A
Express.js: 10,000+ third-party packages | FastAPI: N/A
Express.js: None (third-party required) | FastAPI: No (requires external library)
Express.js: Third-party package required | FastAPI: N/A
Development Speed (Median Project Timeline)
Express.js: 2.7M+ (npm) | FastAPI: 500,000+ (PyPI)
Express.js: 64,000+ | FastAPI: 75,000+ stars
Express.js: ~85% | FastAPI: 22% (Stack Overflow 2024)
Express.js: Manual (requires express-swagger-jsdoc or similar) | FastAPI: Native (Swagger UI + ReDoc built-in)
Express.js: Optional (TypeScript) | FastAPI: Native (Python type hints)
Express.js: ~8,000 req/s | FastAPI: ~28,000 req/s
Express.js: 15 minutes | FastAPI: ~5 minutes
Express.js: ~55 MB per instance | FastAPI: 50-100MB
Express.js: Native Socket.io integration | FastAPI: N/A
Express.js: Requires Node bindings/bridges | FastAPI: N/A
Express.js: 64,000+ stars | FastAPI: N/A
Express.js: 16.2 million | FastAPI: ~1.2M (PyPI: ~2.8M)
Express.js: Via @types/express | FastAPI: N/A
Express.js: 500,000+ | FastAPI: ~30,000 questions
Express.js: Partial (middleware adapters needed) | FastAPI: Native first-class support
Express.js: Callback-based (req, res, next) | FastAPI: N/A
Express.js: 15 years (since 2010) | FastAPI: N/A
Express.js: 52KB | FastAPI: 1,200KB (with uvicorn)
Express.js: No | FastAPI: Yes (Pydantic)
Express.js: No (manual setup with Swagger) | FastAPI: Yes (automatic)
Express.js: Promise/async-await (event loop) | FastAPI: Native async/await with asyncio
Express.js: Not included, external libraries needed | FastAPI: Built-in with Pydantic
Express.js: Yes (Promises/callbacks) | FastAPI: Full (async-first)
Express.js: Node.js 12+ | FastAPI: Python 3.7+
Express.js: 28.4 million | FastAPI: 2.5M weekly
Express.js: 410,000+ | FastAPI: ~400K active
Express.js: ~10,000 req/s | FastAPI: ~12,000 req/s
Express.js: 20-30 hours | FastAPI: 30-40 hours
Express.js: ~35-50 MB | FastAPI: ~80-120 MB
Express.js: No (requires Swagger, apiDoc packages) | FastAPI: Yes (Swagger UI + ReDoc automatic)
Express.js: No (requires middleware like celebrate) | FastAPI: Yes (Pydantic built-in)
Express.js: Limited: TensorFlow.js only, requires external API calls | FastAPI: N/A
Express.js: ~64,000 stars | FastAPI: N/A
Express.js: Yes - runs directly with Node.js | FastAPI: N/A
Express.js: Limited via adapters | FastAPI: N/A
Express.js: Optional (requires setup) | FastAPI: N/A
Express.js: None (requires external libraries) | FastAPI: N/A
Express.js: 8,000-12,000 req/sec | FastAPI: N/A
Express.js: 5-7 days for JS developers | FastAPI: N/A
Express.js: 32% of Node.js projects | FastAPI: N/A
Express.js: ~8,000 req/sec | FastAPI: N/A
Express.js: ~400-600 ms | FastAPI: 250-500ms
Express.js: ~40-100 MB (with node_modules) | FastAPI: N/A
Express.js: ~10,000 per instance | FastAPI: N/A
Express.js: No | FastAPI: Yes (Swagger/ReDoc)
Express.js: ~20M+ (NPM/week) | FastAPI: ~2.8M (PyPI/month)
Express.js: 5-10 minutes | FastAPI: 2-3 minutes
Express.js: 2.3M packages | FastAPI: 500K packages
Express.js: Manual setup required | FastAPI: Built-in (OpenAPI/Swagger)
Express.js: 18M+ weekly downloads | FastAPI: 2.5M+ weekly downloads
Express.js: Requires wrapper middleware (co, async-await-handler) | FastAPI: Yes, built-in by default
Express.js: 12+ years (released 2010) | FastAPI: N/A
Express.js: N/A | FastAPI: 4 years (2021)
Express.js: N/A | FastAPI: No, requires build
Express.js: N/A | FastAPI: Full native support
Express.js: N/A | FastAPI: 2,000+ packages
Express.js: N/A | FastAPI: Built-in (OpenAPI 3.0)
Express.js: N/A | FastAPI: Automatic (Swagger UI + ReDoc)
Express.js: N/A | FastAPI: Requires app server (Uvicorn)
Express.js: N/A | FastAPI: ~2.8M (Jan 2026)
Express.js: N/A | FastAPI: ~15,000 req/s
Express.js: N/A | FastAPI: ~18,000 req/s
Express.js: N/A | FastAPI: 3.5 hours (manual setup required)
Express.js: N/A | FastAPI: ~480,000 packages (PyPI)
Express.js: N/A | FastAPI: Manual setup required
Express.js: N/A | FastAPI: Native, default behavior
Express.js: N/A | FastAPI: ~2,500 extensions
Express.js: N/A | FastAPI: High-level API framework (built on Starlette)
Express.js: N/A | FastAPI: ~15,000-18,000 req/sec
Express.js: N/A | FastAPI: Pydantic (integrated)
Express.js: N/A | FastAPI: ~10,000 req/s
Express.js: N/A | FastAPI: 500,000+ PyPI packages (Python ecosystem)
Express.js: N/A | FastAPI: ~12,000 positions
Express.js: N/A | FastAPI: 6 years (released 2018)
Express.js: N/A | FastAPI: 68,000+ stars
Express.js: N/A | FastAPI: 12 core features
Production Applications (market estimate)
Express.js: N/A | FastAPI: Moderate (3.5/5)
Express.js: N/A | FastAPI: Full (enforced)
Express.js: N/A | FastAPI: No (requires FastAPI-Users, python-jose)
Express.js: N/A | FastAPI: No (requires SQLAlchemy, Tortoise-ORM)
Express.js: N/A | FastAPI: ~350,000 PyPI packages (FastAPI-specific: ~4,000)
Express.js: N/A | FastAPI: 6 (starlette, pydantic, etc.)
Express.js: N/A | FastAPI: Native async/await built-in
Express.js: N/A | FastAPI: ~75,000 stars
Production Readiness Without External Server
Express.js: N/A | FastAPI: Requires ASGI (Uvicorn)
Express.js: N/A | FastAPI: 8,000+ packages
Express.js: N/A | FastAPI: 5 years (since 2018)
Express.js: N/A | FastAPI: No, manual setup required
How to choose between Express.js and FastAPI
Express vs FastAPI — Structured Comparison Data
Machine-readable comparison dataset for Express vs FastAPI. Contains 168 attribute comparisons, 5 FAQ pairs.
Express vs FastAPI — Attribute Category Vocabulary
Taxonomy of attribute categories used to classify comparison data for Express vs FastAPI.
FastAPI is significantly faster, handling ~28,000 requests per second compared to Express's ~8,000 req/s in standard benchmarks—a 3.5x advantage. This is due to FastAPI's async-first architecture and Python's optimizations for I/O-bound operations. For most web applications under moderate load, both are fast enough, but FastAPI excels at high-throughput scenarios.
FastAPI automatically generates interactive OpenAPI/Swagger documentation (Swagger UI + ReDoc) from your code with zero extra work. Express requires manual setup using libraries like Swagger UI or OpenAPI, which adds development time. FastAPI's documentation is also more interactive and machine-readable by default.
Which has more libraries and community support?
Express has a significantly larger ecosystem with 2.3M npm packages vs FastAPI's 500K PyPI packages. Express also has 18M+ weekly npm downloads vs FastAPI's 2.5M weekly downloads. However, FastAPI's smaller ecosystem is still comprehensive for API development, and it's growing rapidly (FastAPI usage increased 230% year-over-year in 2023-2024).
FastAPI has native, first-class async/await support throughout the framework. Express supports async/await in routes and middleware, but it's not the default paradigm and requires manual implementation. FastAPI's async is more straightforward and performant for I/O-heavy operations.
Which should I choose for a startup MVP?
FastAPI is ideal for startup MVPs because you can build a production-ready API in days with automatic documentation, built-in validation, and superior performance—reducing DevOps overhead. Express is better if your team already knows JavaScript or needs extensive third-party integrations. Both are viable; it depends on your team's language preference and existing tech stack.
How to Choose Between Express.js and FastAPI
Language & Runtime: Express.js has JavaScript/Node.js, while FastAPI has Python 3.6+.
Consider: Requests Per Second (benchmark)
Requests Per Second (benchmark): Express.js has ~8,000 req/s, while FastAPI has ~28,000 req/s.
Time to First API (minutes): Express.js has 5-10 minutes, while FastAPI has 2-3 minutes.
NPM/PyPI Packages Available: Express.js has 2.3M+ packages, while FastAPI has 500K+ packages.
Automatic API Documentation: Express.js has Manual (Swagger/OpenAPI required), while FastAPI has Built-in (Swagger UI + ReDoc).
Data Validation: Express.js has Manual or external libraries, while FastAPI has Built-in with Pydantic models.
GitHub Stars (2026): Express.js has 65,000+ stars, while FastAPI has 75,000+ stars.