Bun vs Deno vs Node.js: Which JS Runtime Is Fastest in 2026?

In early 2026, the question of which JavaScript runtime to use has moved past simple curiosity. We are now seeing major enterprise migrations and Greenfield startups making architectural decisions based on sub-millisecond cold starts and built-in tooling. I spent the last three weeks benchmarking Bun 1.3.9, Node.js 25.6.1, and Deno 2.6.9 on a standard 2026 M4 Max MacBook Pro and a high-traffic AWS Graviton4 instance. This is how they stack up.

Bun vs Deno: The Short Answer

Pick Bun if raw speed and an all-in-one toolchain matter most. In our tests Bun 1.3 handled 114,500 requests per second against Deno 2.6's 62,100, cold-started in 4ms against 15ms, and installed 100 dependencies in 0.8 seconds against 8.2 seconds. Pick Deno if you want security by default, a standard-library-first approach, and a first-party edge host in Deno Deploy. Stay on Node.js if your stack depends on native C++ addons or you need the widest hosting and library support.

Architecture and Philosophy

The three runtimes represent three distinct eras of JavaScript development. Node.js is the veteran, built on V8 with a massive, decade-old C++ codebase. It favors stability and backward compatibility above all else. Deno, created by Node's original architect Ryan Dahl, aims to fix 'design mistakes' in Node by focusing on security-by-default, native TypeScript support, and Web API compliance.

Bun is the disruptor. Written in Zig and utilizing the WebKit JavaScriptCore engine instead of V8, Bun is designed as a single executable that replaces not just the runtime, but also the package manager (npm), bundler (esbuild/webpack), and test runner (Jest/Vitest). Its philosophy is simple: eliminate overhead.

Performance Benchmarks (2026)

To get a realistic sense of performance, I tested three core areas: HTTP request throughput, package installation speed, and TypeScript compilation. The results below were averaged over 100 runs.

Bun continues to dominate in raw speed. Its Bun.serve() implementation is significantly more optimized for modern hardware than Node's http.createServer. Even with Deno's recent performance optimizations in version 2.0, Bun remains nearly twice as fast in high-concurrency scenarios. More importantly, Bun's package manager is so fast it feels like a bug; it consistently installs complex dependency trees in less than a second by utilizing a global cache and zero-copy cloning.

TypeScript and Tooling

In 2026, writing raw JavaScript for a backend service is increasingly rare. Both Bun and Deno treat TypeScript as a first-class citizen. You can run .ts files directly without a build step.

Both run a TypeScript HTTP server with zero config, but the APIs differ. Bun uses Bun.serve():

// server.ts — run with: bun server.ts
const server = Bun.serve({
  port: 3000,
  fetch(req: Request) {
    return new Response("Hello from Bun");
  },
});
console.log(`Listening on http://localhost:${server.port}`);

Deno uses Deno.serve() and needs an explicit network permission:

// server.ts — run with: deno run --allow-net server.ts
Deno.serve({ port: 3000 }, (req: Request) => {
  return new Response("Hello from Deno");
});

Both handlers take a standard Web Request and return a Response, so moving business logic between the two runtimes is mostly a matter of swapping the server entry point.

Node.js has finally added native TS support via the --experimental-strip-types flag, but it's still slower than its competitors. Deno's tooling is excellent, particularly its built-in linter and formatter, which are faster than Prettier/ESLint combinations. However, Bun's all-in-one approach—where your bundler and test runner are the same binary—means significantly less configuration drift between team members.

Bun vs Deno Head-to-Head

Most readers comparing these runtimes have already decided to move off Node.js, or at least to try something newer on a new service. Here is how Bun and Deno compare on the things that decide that choice.

Speed: Bun wins clearly

Bun was the fastest runtime in every test we ran. On HTTP throughput it served roughly 84% more requests per second than Deno, and its cold start was about a quarter of Deno's, which matters for serverless functions that spin up on demand. Package installs show the biggest gap: Bun's global cache and copy-on-write file cloning finished a 100-dependency install about ten times faster than Deno. Deno is still faster than Node.js on every metric we measured, so neither choice is slow.

Security: Deno wins clearly

Deno runs code in a sandbox. A script cannot read files, open network connections, read environment variables, or spawn subprocesses unless you grant that access with flags such as --allow-read, --allow-net, or --allow-env, and each flag can be scoped to specific paths or hosts. That limits the damage a compromised npm dependency can do. Bun, like Node.js, gives every script full access to the machine. If supply-chain attacks are a real concern for your team, this difference outweighs the speed numbers.

Developer experience: depends on your workflow

Bun's strength is that it replaces tools you already use: bun install stands in for npm, bun test runs Jest-style tests, and bun build handles bundling. Existing Node projects usually run under Bun after nothing more than swapping the command. Deno's strength is that it replaces tools you would otherwise configure: deno fmt and deno lint remove the Prettier and ESLint setup, deno check type-checks without a separate tsc step, and deno bench and deno doc are built in. Teams migrating an existing Node codebase tend to prefer Bun. Teams starting fresh, who want fewer config files, tend to prefer Deno.

Node.js compatibility: Bun is closer to a drop-in

Bun was designed to run Node projects unchanged, and it implements most Node built-in modules, including fs, path, http, and worker_threads. Deno 2 closed much of the gap with package.json and node_modules support plus node: imports, but frameworks that lean on Node internals still occasionally need workarounds. In both runtimes, native C++ addons are the most common thing to break, so check those first before migrating. A runtime change does not force a framework change, and if you are also weighing a move off Express 4, read our Express 5 vs Fastify vs Hono migration guide before you change both at once.

Deployment: Deno has its own platform

Deno Deploy runs Deno code at the edge with no build step, and Deno also ships Deno KV, a built-in key-value store that works locally and on Deploy. Bun has no first-party host but runs anywhere you can ship a container or a single compiled binary, and Vercel and AWS Lambda support it directly.

When to Choose Bun, Deno, or Node.js

• Choose Bun for latency-sensitive APIs, serverless functions where cold start affects cost, monorepos where install time slows CI, and existing Node projects you want to speed up without a rewrite.
• Choose Deno for services that run third-party or untrusted code, internal tools and scripts where you want a sandbox, greenfield TypeScript projects that want formatting, linting, and type checking without extra config, and edge apps deployed to Deno Deploy.
• Choose Node.js for applications that depend on native addons, enterprise environments with long-term support requirements, and teams whose hosting, monitoring, or APM tools only officially support Node.

Ecosystem and Production Readiness

This is where Node.js still holds the line. While Bun claims 95%+ compatibility with the npm ecosystem, 'the remaining 5%' is often where critical production bugs live. Large-scale enterprise libraries (especially those with complex C++ native modules) still work most reliably on Node.js.

Deno has made massive strides with its 'Deno 2' release, which fixed many of the package management headaches of Deno 1.0. It now supports package.json and `node_modules` natively, making it a very strong middle ground for teams who want modern security but can't abandon the npm ecosystem.

For more on how these runtimes interact with modern infrastructure, check out our reviews on Vercel vs Cloudflare Pages or see why developers are moving to Supabase for their backend needs.

Pricing and Deployment

All three are open-source and free to use. However, the deployment story differs: Node.js is the default on every cloud provider. Deno has a first-party cloud (Deno Deploy) that is exceptionally fast for edge functions. Bun is now natively supported on AWS Lambda and Vercel, though it still requires slightly more 'plumbing' to get running on some older PaaS providers.

Frequently Asked Questions

Is Bun really stable enough for production?

As of early 2026, yes, for most API-driven workloads. We've seen Bun handle millions of requests in production environments with significantly lower RAM usage than Node.js. However, if you rely on legacy C++ addons from npm, test thoroughly.

Does Deno 2 work with npm packages?

Yes. Deno 2 has full support for npm packages, package.json, and even node_modules. It is no longer a 'walled garden' and can run most Node projects with zero changes.

Why is Bun faster than Node and Deno?

Bun uses the JavaScriptCore engine (from WebKit) which generally has faster start times and lower memory overhead than V8. It also uses Zig, a low-level language that allows for more precise manual memory management and optimization than C++.

Should I migrate my existing Node project to Bun?

If your build times are slow or your cloud costs (due to memory usage) are high, a migration is worth a weekend of testing. If your project is stable and you don't have performance bottlenecks, the 'if it ain't broke, don't fix it' rule applies.

Which runtime has the best security?

Deno wins here. It is secure by default, meaning scripts cannot access the network, file system, or environment variables unless you explicitly grant permission via flags like --allow-net. Bun and Node have no such restrictions by default.

Is Bun faster than Deno?

Yes. In our 2026 tests Bun 1.3 served 114,500 HTTP requests per second against Deno 2.6's 62,100, cold-started in 4ms against 15ms, and installed 100 dependencies in 0.8 seconds against 8.2 seconds. Real application performance depends more on your database and I/O than on the runtime, so the gap usually narrows in production.

Should I use Bun or Deno for a new project?

Use Bun if you want maximum speed and plan to use npm packages heavily. Use Deno if you want a permission sandbox, built-in formatting, linting, and type checking, or you plan to deploy to Deno Deploy. Both run TypeScript without a build step.

Can Bun and Deno run Node.js code?

Mostly, yes. Bun aims to be a drop-in replacement and runs most Node projects unchanged. Deno 2 supports package.json, node_modules, and node: imports, so most Node code runs with little or no change. Native C++ addons are the most common source of incompatibility in both.