Comparison

FastAPI vs Flask

On the evidence we track, FastAPI leads this comparison with a composite score of 73/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.

Machine formatsJSONMarkdownGraphQLor send Accept: application/json
FastAPI73
Flask63
Score
Vioscale score
FastAPI73 / 100high · 78%updating
Flask63 / 100medium · 68%updating
Pricing
Free tier
FastAPI
Flask
Model
Price level
FastAPIfree
Flaskfree
Integrations
Count
FastAPI11
Flask
Reliability
Status page
FastAPI
Flask
Adoption
Dependent repos
FastAPI43,608
Flask119,058
Github stars
FastAPI101,862
Flask72,136
Package downloads weekly
Flask
Stackoverflow questions
FastAPI31,000
Flask
Activity
Commits last 30d
FastAPI210
Flask16
Release
Cadence days
FastAPI14
Flask63
History
FastAPI20 items
License
Spdx
FastAPIMIT
Language
Primary
FastAPIPython
FlaskPython
Content
Faq
FastAPI8 items
Flask

Capabilities

Feature-by-feature on the axes that matter for web frameworks. “-” means undocumented, not absent.

Core
Rendering model
FastAPI-
FlaskServer-side
File-based routing
FastAPI-
Flask
Language
FastAPIPython
FlaskPython
Rendering
Server components
FastAPI-
Flask-
Streaming SSR
FastAPI-
Flask
Fullstack
Built-in API / backend routes
FastAPI
Flask
DX
First-class TypeScript
FastAPI-
Flask
Fast refresh / HMR
FastAPI
Flask
Deployment
Edge runtime support
FastAPI-
Flask-

What each one is

The product in its own terms, so the numbers below have context.

FastAPI

Leader

FastAPI is a modern web framework for constructing APIs in Python that combines high performance with developer convenience through automatic validation, interactive documentation generation, and first-class type hint support.

Independently observed

Flask

Flask is a Python-based web framework that emphasizes ease of use and quick setup while supporting complex applications. It provides built-in routing, template rendering, and session management, with extensibility through community-maintained extensions.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

FastAPI

Leader
Open sourceFree tier
as of verify ↗

Flask

Open sourceFree tier
as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
Web
FastAPI
Flask
CLI
FastAPI
Flask
Deployment
Cloud / SaaS
FastAPI
Flask
Self-hosted
FastAPI
Flask

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

FastAPI

Leader
11 total
  • Starlette
  • Pydantic
  • OpenAPI
  • JSON Schema
  • Swagger UI
  • ReDoc
  • OAuth2
  • JWT
  • HTTP Basic authentication
  • Cookies
  • Session management
Independently observed

Flask

Not documented yet.

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.