# niieani/typescript-vs-flowtype

Differences between Flowtype and TypeScript -- syntax and usability

Repository: https://github.com/niieani/typescript-vs-flowtype
Canonical: https://ross.abutalabs.com/products/typescript-vs-flowtype
License: MIT
License Family: permissive
Topics: typescript, flow, flowtype, documentation, comparison, reference, typing, javascript-tools, hacktoberfest
Last push: 2020-02-29T23:53:44+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3541, "days_push": 2377, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1728, forks 76 (observed 2026-08-28T04:05:28.362604+00:00)

## What it is
A community-maintained reference document comparing the syntax, usage, and usability of TypeScript and Flow type checkers. It catalogs differences in IDE support, type safety, expressiveness, and language features between the two systems.

## Use cases
- compare typescript and flow syntax differences
- decide between flow and typescript for a project
- migrate from flow to typescript
- find flow equivalents of typescript features
- learn how flow type soundness differs from typescript
- reference for type system syntax in javascript

## When to choose
- you are evaluating TypeScript vs Flow for a JavaScript codebase
- you need a side-by-side syntax reference while migrating between the two type systems
- you want a quick overview of usability and tooling differences

## When to avoid
- you need up-to-date coverage of recent TypeScript or Flow versions (document targets TS 3.7 and Flow 0.101)
- you need a type checker or tool rather than documentation
- you need benchmarks of type-checking performance (marked as missing)

## Facets
- artifact type: learning-resource
- maturity: maintenance
- function: documentation, type-system
- domain: programming-languages, documentation, developer-tools, web-development
- platform: -
- tags: typescript, flowtype, comparison-guide, reference, type-checking, javascript, web-server, nodejs

## Member repositories
- niieani/typescript-vs-flowtype (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:28.362604+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:32:13.126633+00:00, confidence not recorded.
  - readme: https://github.com/niieani/typescript-vs-flowtype (fetched 2026-08-28T04:05:28.362604+00:00, sha 841b80b3a5ad)
- Data as of 2026-08-30T08:39:29.467469+00:00.