Happy New Year. While most sensible people are recovering from last night’s celebrations, I’m doing what I always do on January 1st — thinking about the year ahead and taking stock of where the tools I rely on daily are heading. And few areas have seen as much productive competition recently as the JavaScript runtime space.
The State of Node.js#
Node.js remains the backbone of server-side JavaScript, and the project had a strong 2025. Node.js 22 became the active LTS release in October, bringing several features that address long-standing pain points.
The built-in test runner, first introduced experimentally in Node 18, has matured considerably. It’s not going to replace Jest or Vitest for complex testing scenarios, but for straightforward unit testing without the overhead of a test framework dependency, it’s remarkably capable. I’ve started using it for utility libraries and internal tools, and the reduction in devDependencies is refreshing.
The --experimental-strip-types flag, which allows running TypeScript files directly by stripping type annotations, is perhaps the most significant quality-of-life improvement in recent memory. While it doesn’t perform type checking (you still need tsc for that), the ability to run .ts files without a compilation step removes friction from the development workflow. For scripts, prototypes, and small services, this is a game-changer.
Permission model improvements continue to bring Node closer to a security-first approach. Being able to restrict file system access, network calls, and child process spawning at the runtime level is something Deno pioneered, and it’s encouraging to see Node adopting similar principles.
Deno 2: Compatibility as Strategy#
Deno 2, which launched in October 2024, represented a strategic pivot that’s paying dividends. By embracing Node.js and npm compatibility, Ryan Dahl’s runtime went from being an idealistic alternative to a practical choice for production workloads.
The numbers tell the story: Deno 2 can import npm packages directly, supports package.json, and works with the vast majority of the Node ecosystem without modification. The “clean break” philosophy of Deno 1 was intellectually appealing but practically limiting. Deno 2 acknowledges that the npm ecosystem is too valuable to ignore.
What Deno retains from its original vision is equally important. TypeScript remains a first-class citizen — no configuration, no build step, just write TypeScript and run it. The permissions model is still the default, requiring explicit grants for file system, network, and environment access. And the built-in toolchain (formatter, linter, test runner, bundler) means you can go from zero to production with no third-party dependencies for your development workflow.
I’ve been running a couple of internal APIs on Deno 2 for the past few months, and the experience has been positive. The cold start times are noticeably better than Node for serverless deployments, and the built-in deno serve with its multi-threaded HTTP server handles concurrent load impressively.
Bun: Speed as a Feature#
Bun continues to push the performance envelope. Built on JavaScriptCore rather than V8, Oven’s runtime consistently benchmarks faster than both Node and Deno for common operations — package installation, test execution, bundling, and HTTP serving.
Bun’s approach is maximalist: it’s a runtime, package manager, bundler, and test runner all in one binary. The package installation speed alone is enough to make you reconsider your toolchain. Running bun install on a large project and watching it complete in seconds rather than minutes is genuinely delightful.
The SQLite driver built into the runtime is a clever move for applications that need local persistence without the overhead of an external database. Combined with Bun’s built-in S3 client and HTML rewriter, there’s an opinionated but pragmatic approach to common web development needs.
Where Bun still faces challenges is ecosystem compatibility. While compatibility has improved dramatically throughout 2025, there are still edge cases where Node.js native modules or complex npm packages don’t work correctly. For greenfield projects, this is manageable. For migrating existing Node applications, it requires careful testing.
Choosing the Right Runtime#
After working with all three runtimes in production over the past year, here’s my practical guidance:
Choose Node.js when you need maximum ecosystem compatibility, have extensive existing Node infrastructure, or are working in enterprise environments where LTS support and stability are paramount. Node isn’t exciting, but it’s reliable, and in production, reliable wins.
Choose Deno when you’re starting a new project, value TypeScript-first development, and want strong security defaults. The developer experience is the most polished of the three, and the compatibility with npm packages means you’re not sacrificing the ecosystem.
Choose Bun when performance is a primary concern, you’re building new services that can work within Bun’s compatibility boundaries, or you want the fastest possible development iteration cycle. The speed improvements are real and meaningful.
My Take#
What I find most encouraging about the current state of JavaScript runtimes is the competitive pressure driving innovation. Node.js is adopting good ideas from Deno (permissions, TypeScript support). Deno is adopting pragmatism from the Node ecosystem (npm compatibility). Bun is pushing everyone on performance.
This is how healthy ecosystems evolve. Instead of a single dominant runtime growing complacent, we have three viable options that keep each other honest. Features that were experimental luxuries two years ago — native TypeScript support, built-in test runners, permission models — are now table stakes.
As someone who wrote their first Node.js application back when it was still a curiosity and callbacks were the only game in town, the sophistication of today’s JavaScript runtime ecosystem is remarkable. We’ve come from callback hell to a world where you can choose between three production-grade runtimes, each with built-in TypeScript support, modern API designs, and performance that would have seemed impossible a decade ago.
The JavaScript runtime story in 2026 is one of abundance. Choose the tool that fits your needs, and know that whichever you pick, you’re building on a solid foundation.