Bun vs Deno vs Node.js

Which One Should You Actually Use?

Not too long ago, this wasn’t even a question. You wanted to run JavaScript on a server? You used Node. That was it. That was the whole conversation.

Then Deno came along and made some developers go “hm, interesting.” Then Bun showed up and made everyone go “wait, why is this so fast.” And now here we are — three runtimes, all legitimate, all with real reasons to use them, and everyone has an opinion.

So let’s actually talk through them. Not just specs and benchmarks, but what it’s like to use each one and when it actually makes sense.

First, a Quick Intro to Each

Node.js — The One That Started It All

Node has been around since 2009. It’s built on Chrome’s V8 engine, it runs half the internet, and it has an absolutely enormous ecosystem behind it. If you’ve been writing JavaScript for any length of time, you’ve used Node — probably without even thinking about it. It’s the default. The thing you reach for without questioning it.

Deno — The Thoughtful Reboot

Here’s something interesting: Deno was built by the same person who built Node. Ryan Dahl spent years thinking about the decisions he made with Node and eventually said, essentially, “okay let me try that again.” Deno launched in 2020 with TypeScript support out of the box, a security model that actually makes sense, and no node_modules folder. It felt like someone had cleaned up a messy room.

Bun — The New Kid Who’s Annoyingly Good

Bun came out in 2022 and its whole pitch was basically “what if everything was just… faster.” It’s built on a different engine than Node (JavaScriptCore instead of V8), it runs TypeScript natively, it has a built-in bundler and test runner, and its package manager makes npm feel like it’s running through mud. It’s newer and still maturing, but it’s hard to ignore.

Let’s Talk About Speed

Bun is fast. Like, genuinely, noticeably fast — not just in synthetic benchmarks but in things you actually feel day to day. Package installs that took 30 seconds in npm finish in 2. Servers that spin up slowly in Node start almost instantly in Bun.

Deno sits roughly in Node territory — sometimes a bit faster, sometimes not, depending on what you’re doing. Neither of them are slow by any real-world measure, but if you put all three side by side in a benchmark, Bun tends to pull away.

That said — if your app is already fast enough, “even faster” might not be the thing you need right now. Node’s performance has never really been the reason people move away from it.

TypeScript — This One’s Simple

Bun and Deno both run TypeScript files directly. No tsconfig, no build step, no extra dependencies. You just write a .ts file and run it. Done.

Node doesn’t. You need to either compile your TypeScript first, use something like ts-node, or set up a loader. It’s not hard, but it’s an extra step, and it’s one of those things that feels a bit dated compared to the other two.

If you write TypeScript — and most people do these days — Bun and Deno have a meaningful edge here right out of the box.

The Package Situation

Node and npm

Over two million packages. That’s the npm registry. Whatever you need to build, someone has probably already built a package for it. This is Node’s biggest advantage and honestly nothing else is close. The downside is that node_modules can spiral into something terrifying, and npm installs aren’t exactly known for being quick.

Bun’s package manager

Bun is compatible with npm and uses the same registry, but installs packages dramatically faster — often 10 to 25 times faster than npm. It still uses a package.json, so you can drop it into an existing Node project and it just works. Even if you’re not ready to switch runtimes entirely, using Bun just for package installs is worth considering.

Deno’s approach

Deno originally took a very different path — importing packages directly from URLs instead of using npm at all. It’s added npm compatibility in newer versions, and it has its own registry called JSR which is genuinely well-designed. But if your project depends heavily on the npm ecosystem, Deno still requires a bit more wrangling than the other two.

Security — Deno Actually Did Something Different Here

By default, a Deno script can’t touch your file system, can’t make network requests, can’t read environment variables. You have to explicitly grant those permissions when you run it. Want network access? Add --allow-net. Want file access? Add --allow-read. It feels a bit annoying at first and then you realize it’s actually a pretty smart idea — especially when you’re running third-party code you didn’t write.

Bun has been adding permissions features, but it’s not as strict by default. Node has been slowly adding a permissions model too, but historically it just runs with whatever access the system user has. Which is fine until it isn’t.

This probably matters more if you’re thinking about supply chain security or running untrusted code. For most apps, it’s not the first thing you think about — but Deno’s approach is genuinely ahead of the curve here.

What Comes in the Box

One of the more underrated differences between these three is what you get without installing anything extra.

  • Node.js ships lean. No bundler, no test runner, no formatter. You assemble your own stack — webpack or esbuild for bundling, jest or vitest for testing, prettier for formatting, eslint for linting. Maximum flexibility, maximum setup time.
  • Deno includes a formatter, linter, test runner, documentation generator, and bundler. It also has Deno Deploy for pushing to the edge. It’s opinionated but thoughtfully so.
  • Bun goes furthest — it’s a runtime, package manager, bundler, transpiler, and test runner in a single binary. For new projects especially, you can throw away a lot of your toolchain config and just use Bun for everything.

How Mature Are They Really?

Node.js has been running production applications for over 15 years. Banks use it. Big e-commerce platforms use it. If you need something battle-tested that you know isn’t going to surprise you at 3am, Node is that thing.

Deno is stable and plenty of teams run it in production. The main friction isn’t stability — it’s ecosystem compatibility. Some packages work great, some need workarounds, and you’ll occasionally hit a wall that you wouldn’t hit with Node.

Bun hit version 1.0 in 2023 and it’s been adopted quickly, but it’s the youngest of the three. Most things work. Some things don’t quite yet. It’s moving fast in a good way, but “moving fast” also means the surface is still being smoothed out.

So Which One Should You Actually Pick?

Stick with Node if
  • You’re working on an existing project that already runs on Node — don’t fix what isn’t broken
  • Your team knows the Node ecosystem well and values stability over novelty
  • You need maximum compatibility with npm packages and existing tools
  • You’re deploying somewhere that only officially supports Node
Give Bun a serious look if
  • You’re starting something new and want the fastest setup and runtime performance
  • You’re tired of managing five different tools for bundling, testing, and running code
  • You write TypeScript and want it to just work without a build step
  • You want the npm ecosystem but can’t stand how slow npm installs are
Try Deno if
  • Security is genuinely important to your project and you want proper permission controls
  • You like the idea of a cleaner, more modern take on JavaScript tooling
  • You’re building for the edge and want to use Deno Deploy
  • You’re starting fresh and are okay with a smaller ecosystem in exchange for a nicer developer experience

The Honest Summary

If you’re starting a new project today and you have no strong reason to use Node, Bun is worth serious consideration. It’s fast, it’s simple, and it handles TypeScript without any fuss. Most npm packages work fine in it.

If security or modern standards are what you care about, Deno is genuinely the most thoughtfully designed of the three. It just comes with the trade-off of a smaller ecosystem and occasional npm compatibility headaches.

And if you need something that’s just going to work, has the deepest community, and won’t run into weird edge cases with your dependencies — Node is still the answer. There’s a reason it’s been the default for 15 years.

None of these is a bad choice. That’s kind of the nice thing about where JavaScript tooling is right now.