TypeScript tsconfig.json Generator

tsconfig.json tells the TypeScript compiler how to compile your project — what files to include, which ES version to target, and what strictness to apply. You need one for any TypeScript project. Without it, tsc falls back to defaults that are often too permissive and don't match your runtime environment.

Use Strict for new projects — it enables all type safety features and sets you up for maintainable code. Use Next.js or React for frontend apps (these set jsx and DOM lib). Use Node for backend services (Node16/NodeNext modules). Use Base for a minimal config you'll customize yourself.

strict: true enables: strictNullChecks (no implicit null), noImplicitAny (all values must have types), strictFunctionTypes (function parameter contravariance), strictBindCallApply (correct bind/call/apply types), strictPropertyInitialization (class properties must be initialized), and noImplicitThis. Enabling strict is the single best thing you can do for type safety.

module: ESNext outputs ES modules (import/export syntax) and is correct for bundlers like Vite, esbuild, and webpack. module: Node16 or NodeNext is for Node.js projects running without a bundler — it enforces .js extensions on imports and respects package.json 'exports'. Use Node16/NodeNext for Node CLIs and libraries; use ESNext for bundled apps.

moduleResolution: bundler (added in TypeScript 5.0) matches how modern bundlers (Vite, esbuild, Rollup) resolve modules — it allows extensionless imports, respects 'exports' in package.json, and doesn't require .js extensions on relative imports. It's the correct choice for Vite + React, Next.js 13+, and most frontend toolchains.

Use isolatedModules when your build pipeline uses a transpile-only tool (Babel, esbuild, SWC, Vite) instead of tsc to compile TypeScript. These tools process files one at a time and can't use type information from other files. isolatedModules: true tells TypeScript to error when you write code that can't be safely transpiled in isolation (like const enum, namespace imports, etc.).