Developer Runtime Showdown: ts-node vs Deno vs Bun for TypeScript Development

Quick summary: The best runtime depends on your needs. ts-node is ideal when you want minimal changes to Node workflows, Deno is opinionated and secure with built-in tooling, and Bun prioritizes raw performance and bundling speed. This review breaks down practical trade-offs.

“Pick the runtime that matches your team's constraints — not the one with the flashiest benchmark.”

Overview of contenders

• ts-node: Runs TypeScript in Node by compiling on the fly or using transpiled caches. Best when you rely on Node ecosystem and want gradual adoption.
• Deno: Runtime created by Node’s original author. Comes with a secure-by-default model, built-in TypeScript support, and standard utilities.
• Bun: New runtime focused on speed — includes a bundler, transpiler, and runtime optimizations. Works well for dev servers and fast local iteration.

Developer Experience (DX)

ts-node integrates smoothly into existing Node projects: start scripts, mocha/jest runners, and nodemon-based reload workflows are straightforward. Deno simplifies setup for greenfield projects because it includes tooling (formatter, bundler, linter). Bun gives blazing-fast install and start times, but the ecosystem is smaller, and native addons need careful handling.

Performance

Bun often wins benchmarks for cold starts and package installs. Deno performs well for I/O-heavy workloads and offers predictable performance with Rust under the hood. ts-node’s performance depends on your compile strategy (transpile-only, caching). For production, transpiling to JS and running on Node is still a typical pattern.

Security and APIs

Deno’s permission system is a differentiator: scripts explicitly request network, file, or environment access. ts-node does not provide such a boundary — you rely on Node’s ecosystem and process-level constraints. Bun is emerging; it currently lacks Deno’s granular permissions model.

Ecosystem compatibility

ts-node + Node wins when you rely on npm packages with native bindings or established libraries. Deno has shims and compatibility layers but some packages need to be adapted. Bun supports npm packages but occasionally suffers compatibility gaps due to different native APIs.

Production readiness

ts-node is commonly used in development; production setups transpile to plain JS and run on Node for stability. Deno is production-ready for some teams and offers a secure runtime, but operational familiarity matters. Bun is improving rapidly and is suitable for experimental or performance-sensitive services where the team can own the runtime stack.

When to choose what

• Choose ts-node if you need minimal migration and rely on existing Node tooling.
• Choose Deno for secure-first greenfield projects or when you want integrated tooling.
• Choose Bun for maximal local iteration speed and for projects willing to embrace a newer runtime.

Benchmarks and practical results

In local tests of dev server start time and module install:

• Bun: fastest cold start and install times.
• Deno: steady performance and small binary size for single-file deployments.
• ts-node: fast with caching, but dependent on ts-node/register or compiled caches.

Pros and cons

ts-node: + ecosystem, - production conventions needed.

Deno: + security, + tooling, - ecosystem adaptation.

Bun: + speed, - ecosystem and maturity.

Conclusion

There is no universal winner. If you need quick wins with low migration cost, stay with ts-node and Node. If you want to embrace opinionated tooling and security, Deno is compelling. If raw developer speed is your objective, experiment with Bun while being prepared for compatibility work.

Recommendation: Prototype a critical path of your app on the new runtime before committing to it in production.