Comparison
Bun or Node.js? Speed now against stability later
The verdict
Run production services on Node.js, and use Bun today for package installs, tests, scripts and build tooling - which is where it delivers the largest wins with the smallest downside. Bun is genuinely faster on its own benchmarks: Bun's published Express-over-HTTPS test (Bun 1.4 against Node.js 26.7.0, bun.sh) shows 48,243 requests per second against 25,181, with lower peak memory. What Bun still does not have is an LTS program. The memory-drift objection has been narrowed, not removed: Bun 1.4, released in August 2026 as a rewrite from Zig to Rust, fixed specific leaks (Bun's own post shows a Next.js App Router pattern that grew without bound in 1.3 settling at 238 MB over 4,000 pages in 1.4), and Bun 1.4.2 in September 2026 still had to fix an AsyncLocalStorage leak introduced in 1.4.1. If your service restarts often or runs short, the risk is small; for a long-running service, run a soak test before trusting it in production.
Bun 1.3 turned the runtime into a full-stack toolkit: a dev server built into Bun.serve with hot module replacement and React Fast Refresh, a unified Bun.SQL client covering Postgres, MySQL, MariaDB and SQLite, a built-in Redis client, isolated installs, dependency catalogs and a security scanner API. Bun 1.4 followed in August 2026 as a ground-up Rust rewrite and the biggest jump in Node API compatibility since 1.0. Node.js 26 shipped in May 2026 as Current with Temporal unflagged and Undici 8, and enters LTS in October 2026 - the same month the project moves to one major release per year, all of them LTS.
Bun vs Node.js on throughput, tooling and risk
Performance figures are published benchmark claims and depend heavily on the workload. The pattern holds up across independent tests: Bun leads on startup, install and raw HTTP throughput, and Node leads on everything to do with operating a service for years.
| Dimension | Bun 1.4 | Node.js 24 and 26 |
|---|---|---|
| HTTP throughput | 48,243 req/s serving a hello-world Express 5.2.1 app over HTTPS (50 connections, Linux x64 EPYC 9R14, Bun's own benchmark on bun.sh). | 25,181 req/s on Node.js 26.7.0 in the same Bun-published test. Vendor benchmark; run your own workload before relying on the ratio. |
| Cold start | Bun's 1.4 post reports a 5.1 ms start on Linux and 15.5 ms on Windows (Bun's own measurement). | Bun does not publish a Node.js start figure; measure it on your own hardware. |
| Memory | In Bun's Express-over-HTTPS test, peak RAM was 105 MB on Bun 1.4 (Bun's own benchmark). | 142 MB peak RAM on Node.js 26.7.0 in the same Bun-published test. |
| Package install | 7 to 25 times faster than npm depending on project size. A React app typically installs in 2 to 5 seconds. | 30 to 45 seconds for the same project with npm. pnpm narrows this considerably. |
| Batteries included | Runtime, package manager, bundler, test runner, dev server, SQL and Redis clients in one binary. | Runtime plus a growing core: stable type stripping, built-in test runner, and a native watch mode. |
| Compatibility | Very high but not total. Native modules using N-API are the usual failure point, and failures are discovered at runtime. | The reference implementation. Every one of the more than 4 million packages on npm targets it. |
| Support model | No formal LTS. You upgrade when Bun ships, and security patching follows the same cadence. | Multi-year LTS with published end-of-life dates, which is what compliance reviews actually ask about. |
When each runtime is the right call
Choose Node.js when
- The process runs for weeks without a restart and a slow leak would page someone at 3am.
- You depend on native addons, image pipelines, gRPC bindings, or anything else built against N-API.
- A customer, auditor, or procurement process needs a named LTS version with a published support window.
- The application is already there and works. Swapping runtimes for a benchmark is not a business case.
- You want the widest set of production-tested libraries and the deepest pool of people who have debugged them.
Choose Bun when
- You are writing CLIs, codemods, monorepo scripts, or anything where a 100 ms startup tax is felt hundreds of times a day.
- CI install time is a real cost. Swapping npm for bun install is the highest-value, lowest-risk change on this page.
- You want one tool instead of five: no separate bundler, test runner, or TypeScript transform to configure.
- The service is short-lived by design - serverless functions, queue workers, request-scoped processes - so leak risk never accumulates.
- You want a single standalone executable to hand someone, which Bun compiles natively.
These are not mutually exclusive
The framing that produces the best outcome in 2026 is not "which runtime do we standardize on" but "which runtime for which job". Plenty of teams run Bun for the API layer and package management while keeping Node for legacy services and any tooling that touches native modules. That split costs almost nothing because both read package.json, both resolve from the same registry, and most application code runs unmodified on either.
If you want to evaluate Bun for a production service, the test that matters is not a benchmark, it is a soak. Run your actual service under representative load for 72 hours and watch resident memory. If the curve is flat, the objection that kept Bun out of long-running production does not apply to your workload and you can proceed with real evidence. If it climbs, you learned that in three days instead of three months.
Node's own trajectory is worth factoring in, because it has been quietly absorbing the reasons people left. Stable type stripping means running .ts files directly with no build step. Node 26 unflagged Temporal and shipped Undici 8. From Node 27 onward the release schedule simplifies to one major each April, promoted to LTS each October, with the odd and even distinction gone entirely - which removes the most common source of confusion about which version to deploy.
The one place the choice is genuinely close is serverless. Bun's faster process start can matter on infrequently hit endpoints, and short-lived functions never run long enough for stability concerns to matter. If your compute is entirely request-scoped, Bun is the runtime this comparison would pick. Details are at bun.com and nodejs.org.
Where this fits in a full stack
The backend and runtime layer covers Deno, the edge runtimes, and the frameworks that sit on top of whichever runtime you pick. If you are standing up a service rather than choosing a runtime in the abstract, the REST and backend API stack guide makes the whole set of calls.
For the command syntax across npm, pnpm and bun, including install and workspace flags, see the npm and package manager cheatsheet. Other matchups are in the comparisons index.