JavaScript to TypeScript — Migration Guides
TypeScript adds static typing to JavaScript, catching entire categories of bugs at compile time rather than runtime. Migrating an existing JavaScript codebase to TypeScript is one of the highest-leverage technical investments a team can make — but it requires a clear strategy to avoid disruption.
JS2TS is a free tool that automatically converts JavaScript code to TypeScript, adding type annotations and updating syntax. This category covers everything you need to know about the JS-to-TS migration process.
Topics Covered
- Migration strategies — Incremental migration, allowJs, strict mode progression, and team-friendly rollout plans
- Type annotations — Adding types to functions, variables, objects, arrays, and class members
- tsconfig setup — Compiler options, strict flags, path aliases, and project references
- Common patterns — Converting callbacks, Promises, React components, Express routes, and utility functions
- Third-party types — @types packages, declaration files, and handling untyped libraries
- Tooling — ESLint with TypeScript, ts-node, build pipeline integration
Browse the articles below or use the JS2TS converter to automatically convert your JavaScript files to TypeScript.
