Features
- Secure by default with explicit permissions
- Native TypeScript support without configuration
- Web-standard APIs (fetch, Web Workers, import maps)
- Built-in formatter, linter, test runner, and benchmarker
Pros
- Security-first design prevents accidental file/network access
- Excellent TypeScript and web standards alignment
- Deno Deploy for edge serverless hosting
Cons
- Smaller ecosystem than Node.js despite npm compatibility
- Permission flags add friction to development workflow
- Some popular Node.js libraries still have compatibility issues
Overview
Deno is a JavaScript and TypeScript runtime created by Ryan Dahl, the original creator of Node.js, designed to address what he considered mistakes in Node’s design. It runs TypeScript natively, uses web-standard APIs, and is secure by default — scripts cannot access the file system, network, or environment variables without explicit permission flags.
Deno includes a comprehensive standard library, a built-in formatter, linter, test runner, and a dependency inspector. With Deno 2, it added full npm compatibility, making it practical to use existing Node.js packages while benefiting from Deno’s security model and developer tooling.
When to Use
Deno is ideal when security is a priority (sandboxed execution), when you want first-class TypeScript without configuration, or when deploying to edge environments via Deno Deploy. It’s also a strong choice for scripts and CLI tools that benefit from its permissions model.
Getting Started
curl -fsSL https://deno.land/install.sh | sh
# Run a TypeScript file directly
deno run --allow-net server.tsDeno.serve({ port: 3000 }, (_req) => {
return new Response("Hello from Deno!");
});