facebook/flow
Adds static typing to JavaScript to improve developer productivity and code quality. observed · 2026-08-28
Health v2 · maintenance only
95/100
- Activity 99
- Release rhythm 87
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: 5.0
- age_days: 4327
- days_rel: 11
- days_push: 7
- n_releases_24m: 111
Adoption not part of the score
22279 stars · 1890 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded
Flow is a static type checker for JavaScript, now a typed dialect of JavaScript written in Rust. It catches type errors via annotations and offers first-class React component syntax and pattern matching.
Use cases
- add static typing to a JavaScript codebase
- type-check React components with first-class component syntax
- catch type errors before runtime in JS projects
- migrate from TypeScript to a stricter type checker
- strip Flow type annotations with Babel or flow-remove-types
- parse Flow-typed JavaScript to get an annotated syntax tree
When to choose
- you want stronger static guarantees than TypeScript, like exact-by-default object types
- your project is React-heavy and benefits from component and renders syntax
- you want built-in pattern matching with exhaustiveness checks
When to avoid
- your team and ecosystem already standardize on TypeScript
- you need a typechecker that also emits JavaScript (Flow requires a separate build step)
- you rely on TypeScript-only features or its much larger ecosystem
Facets
cli-tool · maturity active
type-system linter parser cli developer-tools programming-languages web-development frontend developer-tools windows cli static-type-checker javascript react typescript-alternative rust macos linux nodejs
8 sources
- readme: https://github.com/facebook/flow · fetched 2026-08-28 · baac2b03f543
- homepage: https://flow.org/ · fetched 2026-08-29 · 7a8e4fe14417
- site_page: https://flow.org/en/docs/getting-started · fetched 2026-08-29 · c851d9768281
- site_page: https://flow.org/en/docs · fetched 2026-08-29 · 1a6376963469
- site_page: https://flow.org/en/docs/flow-vs-typescript · fetched 2026-08-29 · d6265bec7c16
- site_page: https://flow.org/en/docs/react/component-syntax · fetched 2026-08-29 · c67a895df9b8
- site_page: https://flow.org/en/docs/match · fetched 2026-08-29 · fae2e56a66cf
- site_page: https://flow.org/en/docs/types/objects · fetched 2026-08-29 · be1715476070
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| facebook/flow | main | 95 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem