# airbnb/ts-migrate

A tool to help migrate JavaScript code quickly and conveniently to TypeScript

Repository: https://github.com/airbnb/ts-migrate
Canonical: https://ross.abutalabs.com/products/ts-migrate
Language: TypeScript
License: MIT
License Family: permissive
Topics: typescript, javascript, codemod, migration
Last push: 2026-01-22T00:09:47+00:00

## Health v2 (maintenance only)
Score: 61/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 63, release rhythm 35, longevity 100
- inputs: {"age_days": 2463, "days_push": 224, "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 5617, forks 233 (observed 2026-08-28T04:09:23.046205+00:00)

## What it is
ts-migrate is a CLI tool from Airbnb that converts JavaScript or partial TypeScript projects into compiling TypeScript projects using a plugin-based codemod pipeline. It accelerates large-scale migrations by producing code that builds immediately, though it relies on @ts-expect-error and any annotations that require later cleanup.

## Use cases
- migrate a large JavaScript codebase to TypeScript
- convert frontend app from JS to TS quickly
- codemod a partial TypeScript project to fully compile
- reignore existing TypeScript errors after upgrading
- write custom migration plugins for codebase-specific transforms

## When to choose
- you need to migrate a large JavaScript codebase to TypeScript incrementally and get a compiling build fast
- you want a plugin-based, customizable codemod framework for TS migrations
- you need to suppress and triage type errors at scale with a reignore pass

## When to avoid
- you want fully type-safe output with no manual cleanup
- you are starting a new project and can write TypeScript from scratch
- your codebase is small enough to migrate by hand

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: developer-tools, build-tool, parser
- domain: developer-tools, programming-languages, frontend, web-development
- platform: cli, cross-platform
- tags: typescript, codemod, migration, javascript-to-typescript, code-transformation, nodejs

## Member repositories
- airbnb/ts-migrate (main) score 61

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:23.046205+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 2026-08-29T17:55:24.121800+00:00, confidence not recorded.
  - readme: https://github.com/airbnb/ts-migrate (fetched 2026-08-28T04:09:23.046205+00:00, sha 4c5ffde76bc0)
  - registry_npm: https://registry.npmjs.org/ts-migrate (fetched 2026-08-29T08:50:27.408051+00:00, sha 4586008767f2)
- Data as of 2026-08-30T08:39:29.467469+00:00.