Node.js vs Deno vs Bun

Node.js was the dominant JavaScript runtime for server-side development for a long time. However, the JavaScript ecosystem has since evolved, and new competitors have emerged to challenge Node.js's position.

In recent years, Deno and Bun have emerged as notable alternatives, each offering unique features and advantages. They've generated a lot of hype, leading you to question whether it's time to move away from Node.js and switch to either Bun or Deno.

This article will compare Node.js, Deno, and Bun, guiding you toward making an informed choice for your next project.

Let's get started!

What is Node.js?

Node.js is an open-source runtime environment built on Google’s V8 JavaScript engine. It was released in 2009 and is one of the most mature JavaScript runtimes. Node.js's extensive ecosystem is powered by npm, one of the most comprehensive package registries.

What is Deno?

Deno is an open-source runtime created by the original developer of Node.js to address various issues identified in Node.js. It was written in Rust and also uses the V8 engine. Deno supports loading dependencies via URLs, whether local or remote. It features built-in TypeScript support and has been working towards better compatibility with Node.js over time.

What is Bun?

Bun is a new open-source runtime for JavaScript, released in 2021. It focuses on performance and developer experience, using the WebKit's JavaScriptCore instead of the V8 engine like Node.js and Deno. It was written in Zig and aims to be a faster, drop-in replacement for Node.js. It includes features such as built-in TypeScript support and comes with tools for testing and creating executables, among others.

Runtime comparison: Node.js, Deno, and Bun

Before diving into a detailed comparison of features, this section provides a table that offers an overview and summary of how Node.js, Deno, and Bun stack up across key categories.

Here's how Node.js, Deno, and Bun compare:

Performance

Performance is a critical factor when assessing the efficiency and responsiveness of an application. Bun has been heavily marketed for its speed, making performance a significant selling point at its release.

To evaluate whether Bun’s performance claims hold up, I ran benchmarks based on the Bun HTTP Framework Benchmark, focusing on Express. The tests measured average throughput, including handling simple GET requests, extracting path parameters, and parsing JSON bodies.

Here are the benchmark results:

Bun outperforms both Deno and Node.js, handling over 52,000 requests per second. This confirms Bun’s standing as the fastest runtime when using Express.

Deno also delivers solid performance, averaging 22,286.51 requests per second, but falls behind Bun in raw speed.

Node.js, while dependable, lags significantly, managing only 13,254.55 requests per second on average, positioning it as the slowest of the three.

In terms of speed and efficiency, Bun takes the clear lead.

Dependency management

This section examines the differences in dependency management among Node.js, Deno, and Bun.

Below is a comparison table that highlights how each runtime handles dependencies:

Node.js relies on npm for managing packages. The npm ecosystem revolves around the package.json file, which lists dependencies and scripts that define a project’s structure. The dependencies are installed into a node_modules directory. Node.js supports both CommonJS and ES modules, but transitioning to ES modules has been challenging. It requires flags, adjustments to package.json, or command line configurations to achieve full compatibility.

Deno takes a different approach to dependency management by eliminating the need for a package.json file; instead, it uses direct URL imports and supports import maps for organizing dependencies. Deno is ES module-first and initially did not support CommonJS modules to avoid the complexity of managing multiple module systems. However, with the release of Deno 2, it added CommonJS support, enhancing compatibility with the Node.js ecosystem:

Bun uses a package.json file like Node.js but enhances the process with a binary lockfile bun.lockb for faster dependency resolution. While Bun is ES module-first, it also offers robust support for CommonJS, treating it as a first-class citizen. This dual compatibility simplifies working with both modern ES modules and the vast ecosystem of existing CommonJS packages, without the complex configurations often required in Node.js. Bun also supports downloading packages from the npm registry, Git, HTTP, and tarballs, offering flexibility while ensuring efficient package management, all while maintaining performance and security.

Each runtime has its own approach to handling dependencies, and there isn't a clear winner overall. However, Bun stands out by making it easier to work with both ES modules and CommonJS modules, and by allowing packages to be downloaded from a variety of sources, including npm, Git, HTTP, and tarballs.

Tooling

In this section, we'll compare the tooling available in Deno, Bun, and Node.js. Having robust built-in tools can significantly reduce the need to download additional dependencies, helping you get started more quickly.

Here’s how they compare:

Deno leads the pack regarding built-in tooling, offering a REPL, test runner, easy executable creation, and debugger without needing third-party packages. Additionally, Deno includes a built-in linter and formatter, providing a complete development environment out of the box.

Node.js follows closely behind with built-in support for a REPL, test runner, executable creation, and debugger. However, it lacks Deno's built-in linter and formatter, requiring you to rely on external tools for those functionalities.

Bun, while promising, falls short in this comparison. It offers a test runner, the ability to create executables, and a debugger but lacks a REPL, which is helpful for quick experimentation. Additionally, it doesn’t include a built-in linter or formatter, which are standard features in Deno.

For a more comprehensive development experience, Deno and Node.js are the best options, with Deno taking the lead due to its all-in-one toolset.

Built-in TypeScript support

The growing adoption of TypeScript in modern web development has significantly changed how JavaScript runtimes approach built-in language support. Traditionally, you had to configure TypeScript. However, newer runtimes like Deno and Bun have introduced more seamless TypeScript integration.

Here’s a comparison of how the major JavaScript runtimes handle TypeScript:

Deno and Bun lead the way with first-class support for TypeScript. Both runtimes automatically transpile TypeScript files to JavaScript and execute them without needing external tools or configurations. Bun simplifies the setup further by providing a default TypeScript configuration, while Deno’s REPL also supports TypeScript, making it easy to start experimenting.

Node.js has made progress with its experimental TypeScript support. It requires using the --experimental-strip-types flag, which tells Node.js to strip type annotations from .ts files and run them directly. However, this support is limited, handling only inline type annotations and lacking comprehensive TypeScript feature support, such as enums or namespaces. It also requires explicitly using the type keyword for type imports.

If you want to quickly and efficiently start using TypeScript, Deno and Bun offer the best experiences with minimal setup. While Node.js is making strides, its experimental support still needs to catch up to the more integrated approaches found in Deno and Bun.

Across all runtimes, there is no runtime type checking, so you still need to use tools like tsc or configure your IDE for effective type checking during development.

Security

Security is critical to any runtime environment and essential for protecting applications and data. Here’s how Node.js, Deno, and Bun compare in terms of security features:

Deno was built with security as a top priority, featuring a comprehensive permissions model, default sandboxing, and runtime permission requests, making it the most secure runtime for JavaScript out of the box.

Node.js, as the most established runtime, offers robust security tools and has introduced an experimental permissions model in version 20. However, it lacks some of the out-of-the-box security features found in newer runtimes like Deno.

Bun is still developing its security features and lacks a permissions model and sandboxing. While future security audits are planned, it currently fall behind Node.js and Deno regarding security.

Regarding security, Deno is the most secure runtime by default because it can enforce strict permissions for accessing the file system, network, and other sensitive APIs.

Support and community

A large and active community can be important when choosing a runtime. It provides abundant resources and tools, which can significantly boost productivity and problem-solving capabilities.

Here’s an overview of community support, resources, and adoption rates for each runtime:

Node.js offers unparalleled support and community, thanks to its long-standing presence and extensive ecosystem. With millions of developers and plenty of packages available through npm, its maturity and widespread adoption across industries make it a reliable choice for almost any project.

Deno is gradually catching up, particularly appealing to developers who prioritize TypeScript and modern web standards. However, it hasn't yet reached the level of community growth and maturity that Node.js has enjoyed over the past decade. While Deno is making strides, it doesn't yet offer the same breadth of resources as Node.js.

Bun, though newer, is rapidly gaining traction due to its focus on performance and compatibility with Node.js. This allows Bun to take advantage of existing npm packages while pushing the boundaries of what's possible in a modern JavaScript runtime. However, Bun is still less mature than Node.js, lacking features like a REPL, and it has more work to do to become fully stable and reliable for large-scale use.

Adherence to web platform APIs

Web platform APIs ensure consistency and interoperability across different runtime environments. Support for these APIs allows you to write portable code with browser-like functionality in server-side contexts:

Deno and Bun are designed with strong web compatibility, offering extensive support for web APIs that closely mimic browser environments on the server.

When Node.js was first introduced, most web platform APIs were not yet standardized, but significant strides have since been made in adopting these APIs.

All three runtimes—Node.js, Deno, and Bun—offer good support for web platform APIs, making them solid choices depending on your specific needs. If web platform API compatibility is a key factor, any of these runtimes will serve you well.

Built-in data storage

Having built-in data storage within a runtime can be incredibly valuable for quick setups, prototyping, and applications requiring lightweight, embedded databases. This feature also reduces dependency management and can enhance performance due to native integration.

Node.js includes an experimental SQLite driver available under node:sqlite, allowing you to work with an embedded SQLite database natively:

import { DatabaseSync } from "node:sqlite";
const db = new DatabaseSync(":memory:");
const query = db.prepare("SELECT 'Hello world' AS message");
const result = query.get();
console.log(result); // => { message: 'Hello world' }

Bun provides built-in support for SQLite through the bun:sqlite module. It includes features like prepared statements and transactions, and it claims to be faster than better-sqlite3, making it one of the fastest options for SQLite in JavaScript:

import { Database } from "bun:sqlite";

{
  using db = new Database("mydb.sqlite");
  using query = db.query("select 'Hello world' as message;");
  console.log(query.get()); // => { message: "Hello world" }
}

Deno, on the other hand, does not include built-in traditional database support. To use a database with Deno, you must install external packages for specific databases like MySQL, PostgreSQL, or others.

For native, built-in relational data storage, Bun and Node.js stand out as the best options, each offering robust SQLite support directly within the runtime.

Deployment options and project backing

In this section, we'll explore the deployment options available for each runtime and understand the backing behind these projects, giving you a clearer picture of their support and maturity.

Here’s how each runtime stacks up:

Node.js, primarily driven by contributions from a wide range of developers and supported by the OpenJS Foundation, benefits from widespread deployment support across all major cloud providers. While it doesn’t offer its own deployment service, the extensive support makes it easy to deploy Node.js applications in virtually any environment.

Deno, though newer, is expanding its deployment options with Deno Deploy as its flagship service. While Deno can also be deployed on other services, the support isn’t as extensive as Node.js. However, Deno Deploy provides a native solution if you want to leverage Deno’s ecosystem.

Bun currently lacks an official deployment service and doesn’t yet enjoy widespread support across cloud providers. However, as a venture-funded project developed by Oven, it is likely that deployment solutions will emerge in the future. Bun’s deployment options are now more limited than Deno and Node.js.

In terms of deployment, Node.js is the clear winner, as it can be easily deployed in most environments and offers the widest range of options.

Runtime interoperability

Interoperability is useful when choosing a JavaScript runtime, especially for newer options like Deno and Bun, which may have a limited ecosystem of Node.js. Using libraries and tools across runtimes enhances flexibility and reduces adoption barriers.

Here's a quick comparison:

Bun is the most interoperable runtime, designed to be a drop-in replacement for Node.js. It can read package.json, support node_modules, and offers high Node.js API compatibility, making it easy for developers to migrate or experiment while keeping access to the npm ecosystem.

import express from "express";

const app = express();
const port = 8080;

app.get("/", (req, res) => {
  res.send("Hello World!");
});

app.listen(port, () => {
  console.log(`Listening on port ${port}...`);
});

Output:

Deno has made significant progress in Node.js compatibility, now supporting npm packages and package.json through a compatibility mode. While its use of import maps instead of node_modules and partial Node.js API compatibility may require adjustments when porting applications:

import express from "npm:express@4.18.2";
const app = express();
const port = 8080;

app.get("/", (req, res) => {
  res.send("Hello World!");
});

app.listen(port, () => {
  console.log(`Listening on port ${port}...`);
});

Node.js, as the established runtime, doesn’t prioritize compatibility with Deno or Bun-specific features. Instead, it leverages its vast ecosystem and implements the interesting features natively.

Bun excels in interoperability with its strong Node.js compatibility, followed by Deno. As mentioned, Node.js doesn’t require extensive interoperability since it already includes most of the features it needs within its ecosystem.

When to use Node.js, Deno, or Bun

So far, we've looked at various features and factors to consider when choosing a JavaScript runtime. Ultimately, choosing the right runtime for your project involves carefully weighing the strengths and limitations of each option.

If you're already using Node.js and wondering whether it's worth switching, it's generally not necessary to switch. Node.js is constantly evolving, incorporating features from Bun and Deno, such as native TypeScript support, a built-in test runner, an embedded database, and a permissions model. Many features currently exclusive to Bun or Deno will likely be available in Node.js in the future. Additionally, Node.js is more mature, with a rich ecosystem of tools, libraries, and community support, making it a reliable and well-established choice.

However, if you're interested in experimenting with new tools and ideas, speed, Bun and Deno present compelling alternatives. They each offer unique advantages, like Deno’s REPL with built-in TypeScript support and its robust runtime permissions for enhanced security. Bun, on the other hand, excels in speed. Additionally, both Bun and Deno avoid the CommonJS and ES module compatibility issues that Node.js has struggled with. Still, in my opinion, these features alone don’t provide enough reason to switch from the more mature and well-supported Node.js.

Final thoughts

This article has explored the features of Node.js, Deno, and Bun to help you assess which runtime may be best for your project. Hopefully, you now understand their differences, strengths, and weaknesses and can make an informed choice. Once you've decided on the right tool, you can dive deeper by exploring their respective documentation.

Article by

Stanley Ulili

Stanley Ulili is a technical educator at Better Stack based in Malawi. He specializes in backend development and has freelanced for platforms like DigitalOcean, LogRocket, and AppSignal. Stanley is passionate about making complex topics accessible to developers.

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