TypeScript Playground

TypeScript extends JavaScript with static type annotations that catch errors at compile time rather than runtime. The AllTools TypeScript Playground provides an in-browser environment where you can write TypeScript code, see compilation output in real-time, and run the resulting JavaScript — all without installing Node.js, npm, or the TypeScript compiler locally. The playground uses the official TypeScript compiler (tsc) compiled to WebAssembly or loaded as a JavaScript bundle, providing the same type checking and compilation behavior as the CLI compiler. You can experiment with TypeScript features like: type annotations and inference, interfaces and type aliases, generics for reusable typed components, union and intersection types, conditional types for advanced type-level programming, template literal types, utility types (Partial, Required, Pick, Omit, Record), and decorators. The editor provides IntelliSense-style autocompletion, inline error highlighting, and hover-to-reveal type information. The compiler options panel lets you configure strict mode, target ECMAScript version, module system, and other tsconfig settings. All code execution happens in your browser — your TypeScript code, which may contain proprietary algorithms or business logic, never leaves your device.

The TypeScript Playground serves both educational and practical prototyping purposes. For learning TypeScript, the immediate feedback loop — type code, see errors, fix them, see the compiled JavaScript output — accelerates understanding of the type system far faster than configuring a local project. Common learning exercises include: annotating function parameters and return types, creating interfaces for API response shapes, using generics to write type-safe utility functions, implementing discriminated unions for state management, and understanding how TypeScript types erase to JavaScript at runtime. For prototyping, the playground lets you test type-level logic before integrating it into a larger project — complex generic types, conditional types, and mapped types can be developed and verified in isolation. For code review and collaboration, sharing TypeScript snippets with colleagues is easier through a playground than setting up a shared project. For library authors, the playground helps test whether your published types work correctly from the consumer's perspective. The AllTools playground provides this environment privately — unlike the official TypeScript Playground at typescriptlang.org which processes code through their servers, the AllTools version runs entirely in your browser.