---
title: "TypeScript Go (tsgo)"
description: "TypeScript 7 is a native Go port of the TypeScript compiler offering up to 10x faster type-checking. This article covers setup and the TypeScript 5→6 migration changes."
date: "2026-03-24"
tags: ["TypeScript","Tsgo","Frontend","Development"]
canonical: "/learn/guides/project/tsgo"
---

import { Aside } from '@astrojs/starlight/components'
import PackageManagers from '~/components/PackageManagers.astro'

TypeScript 7 is a native Go port of the TypeScript compiler (codenamed
**tsgo**). It targets the same language semantics as TypeScript 5/6 but is
significantly faster — benchmarks show 10× or more improvement on large
codebases.

## TL;DR

Install `@typescript/native-preview` to get the `tsgo` binary (TypeScript 7
dev preview). Separately, apply the TypeScript 6.0 migration checklist to your
`tsconfig.json` to avoid deprecation errors when fully upgrading.

## Installation

<PackageManagers pkg="@typescript/native-preview" dev />

This installs the `tsgo` binary. You can expose it as an optional script for
native checks:

```json title="package.json"
{
  "scripts": {
    "typecheck:tsgo": "tsgo --noEmit"
  }
}
```

<Aside type="caution">
  `@typescript/native-preview` is a **dev preview** and updates daily. It does
  not yet replace the `typescript` package for all tooling. For example,
  `@astrojs/check` currently requires `typescript@^5.0.0` as a peer dependency.
</Aside>

## TypeScript 5.x → 6.0 migration

TypeScript 6.0 is the version that bridges the legacy TypeScript 5 compiler and
the forthcoming TypeScript 7 (tsgo). Most changes are **new defaults** and
**deprecations** preparing for 7.0.

### Changed default values

| Option                         | TS 5 default               | TS 6 default                    |
| ------------------------------ | -------------------------- | ------------------------------- |
| `strict`                       | `false`                    | `true`                          |
| `target`                       | `ES3`                      | `es2025`                        |
| `module`                       | `CommonJS`                 | `es2022` (resolved from target) |
| `moduleResolution`             | `node10`                   | `bundler`                       |
| `rootDir`                      | inferred from source files | `.` (tsconfig directory)        |
| `types`                        | all `@types` auto-included | `[]` (none)                     |
| `noUncheckedSideEffectImports` | `false`                    | `true`                          |
| `libReplacement`               | `true`                     | `false`                         |
| `esModuleInterop`              | `false`                    | `true`                          |

### Deprecated options

All deprecations in TS 6 become **hard removals** in TS 7:

| Deprecated option/value                           | Migration                              |
| ------------------------------------------------- | -------------------------------------- |
| `target: "es3"` / `"es5"`                         | `target: "es2015"` or higher           |
| `downlevelIteration`                              | Remove entirely                        |
| `moduleResolution: "node"` / `"node10"`           | `"nodenext"` or `"bundler"`            |
| `moduleResolution: "classic"`                     | `"nodenext"` or `"bundler"`            |
| `module: "amd"` / `"umd"` / `"system"` / `"none"` | `"esnext"`, `"commonjs"`, `"nodenext"` |
| `baseUrl`                                         | Inline value into `paths` entries      |
| `esModuleInterop: false`                          | Remove (always `true`)                 |
| `allowSyntheticDefaultImports: false`             | Remove (always `true`)                 |
| `alwaysStrict: false`                             | Remove (always strict)                 |
| `outFile`                                         | Use a bundler                          |
| `module Foo {}` namespace syntax                  | `namespace Foo {}`                     |
| `import ... assert {}` import assertions          | `import ... with {}`                   |

### Priority migration checklist

**Priority 1 — likely breaking for most projects:**

1. Set `"types": ["node"]` (or all `@types` packages you need) — types are no longer auto-discovered.
2. Set `"rootDir": "./src"` if you were relying on inference (source files in a subdirectory).
3. Review the new `strict: true` default — set `"strict": false` if not ready.

**Priority 2 — common adjustments:**

1. Set explicit `target` if you need something other than `es2025`.
2. Set explicit `module` if you need CommonJS output.
3. Remove `baseUrl` and inline its value into `paths` entries.
4. Replace `import ... assert {}` with `import ... with {}`.
5. Replace `module Foo {}` with `namespace Foo {}`.
6. If you have side-effect imports that do not resolve, set `"noUncheckedSideEffectImports": false`.

**Priority 3 — deprecated options to remove:**

Remove `downlevelIteration`, `outFile`, `alwaysStrict: false`, `esModuleInterop: false`, `allowSyntheticDefaultImports: false`, and update legacy `moduleResolution` / `module` values.

### Temporary escape hatch

Add `"ignoreDeprecations": "6.0"` to `tsconfig.json` to silence deprecation
warnings while you migrate. This will **not** work in TypeScript 7.

```json
{
  "compilerOptions": {
    "ignoreDeprecations": "6.0"
  }
}
```

### Automated migration tool

The [`ts5to6`](https://github.com/andrewbranch/ts5to6) tool (by a TypeScript
team member) automates the two most disruptive changes — `baseUrl` removal and
`rootDir` inference:

```sh
npx @andrewbranch/ts5to6 --fixBaseUrl .
npx @andrewbranch/ts5to6 --fixRootDir .
```

## Documentation

- [`@typescript/native-preview` on npm](https://www.npmjs.com/package/@typescript/native-preview)
- [typescript-go repository](https://github.com/microsoft/typescript-go)
- [TypeScript 6.0 Beta announcement](https://devblogs.microsoft.com/typescript/announcing-typescript-6-0-beta/)
- [TypeScript 5.x → 6.0 migration guide](https://gist.github.com/privatenumber/3d2e80da28f84ee30b77d53e1693378f)
- [Automated migration tool `ts5to6`](https://github.com/andrewbranch/ts5to6)