tsc --init: create a tsconfig.json file

npx tsc --init writes a tsconfig.json in the current directory with a recommended set of compiler options: strict type checking, modern module/target settings and comments that explain the options you may want to turn on. Since TypeScript 5.9 the template is short (about 40 lines); older versions wrote a very long file with almost every option commented out.

Create the file

npm init -y >/dev/null
npm install --silent --no-audit --no-fund --save-dev typescript@7.0.2 >/dev/null 2>&1
npx tsc --init
grep -v '^ *//' tsconfig.json | grep -v '^ *$'

Created a new tsconfig.json

You can learn more at https://aka.ms/tsconfig
{
  "compilerOptions": {
    "module": "nodenext",
    "target": "esnext",
    "types": [],
    "sourceMap": true,
    "declaration": true,
    "declarationMap": true,
    "noUncheckedIndexedAccess": true,
    "exactOptionalPropertyTypes": true,
    "strict": true,
    "jsx": "react-jsx",
    "verbatimModuleSyntax": true,
    "isolatedModules": true,
    "noUncheckedSideEffectImports": true,
    "moduleDetection": "force",
    "skipLibCheck": true,
  }
}

The grep hides the comment lines so only the active options remain. Without a global install, npx tsc runs the project's own compiler from node_modules/.bin, which keeps the version in package.json.

What the main options mean

rootDir and outDir are commented out: uncomment them (./src and ./dist) to keep compiled files out of the source tree.

Pass options while generating

Any compiler flag given together with --init is written into the file, for example npx tsc --init --rootDir src --outDir dist --module commonjs. That is quicker than editing the JSON afterwards and avoids typos in option names.

Pitfalls

• Errors right after init. The template is strict, and verbatimModuleSyntax with module: nodenext rejects export in a file that Node.js treats as CommonJS (no "type": "module" in package.json), with error TS1287. Add "type": "module" or change module.
• Missing Node.js types. With types: [], using process or require fails with Cannot find name 'process' until you add "types": ["node"] and install @types/node. Module resolution problems show up as TS2307 Cannot find module.
• Comments and trailing commas. tsconfig.json is JSONC: the comments and the trailing comma are valid for tsc and editors, but a strict JSON parser (for example JSON.parse in your own script) rejects them.
• Old tutorials show target: es2016, module: commonjs and esModuleInterop: that was the template before TypeScript 5.9.

Confirm it worked

npx tsc --showConfig prints the final configuration that tsc will use, including the files it found. Running npx tsc with no arguments now compiles the project according to the new file.

FAQ