Bun made its debut in September 2023 as the latest contender in the world of JS runtimes, offering an alternative to Nodejs and Deno. According to its developers, Bun boasts speeds up to five times faster than Nodejs and three times faster than Deno, while also offering a simpler and cleaner syntax compared to Nodejs. This impressive performance is largely due to its use of Zig, one of the newest successors to C. But before we get ahead of ourselves, let's explore why Bun hasn't yet dethroned Nodejs...

Bun advantages

According to the documentation, Bun is designed to be incredibly fast and offers a more straightforward syntax than other JavaScript runtimes.

Bun is a newly developed JavaScript runtime, crafted from the ground up to support the contemporary JavaScript ecosystem. It focuses on three key design objectives:Speed. Bun not only launches quickly but also maintains high performance. It leverages JavaScriptCore, Safari’s high-efficiency JS engine, which is crucial as computing shifts to the edge.Elegant APIs. Bun offers a streamlined collection of highly optimized APIs for routine tasks, such as initiating an HTTP server and file operations.Cohesive DX. Bun serves as an all-in-one toolkit for developing JavaScript applications, featuring a package manager, test runner, and bundler.

Bun is a freshly developed JavaScript runtime created from the ground up to cater to the current JavaScript ecosystem. It focuses on three main design objectives:

Speed. Bun initiates quickly and operates at high speeds. It enhances JavaScriptCore, which is the high-performance JS engine crafted for Safari. As we shift towards edge computing, this becomes increasingly vital.

Elegant APIs. Bun offers a streamlined collection of highly efficient APIs designed to handle everyday tasks, such as launching an HTTP server and managing file operations.

Bun is an all-in-one toolkit designed for building JavaScript apps, offering features such as a package manager, test runner, and bundler.

While all of this might seem tempting, the key question is: How difficult is it to transition between Node.js and Bun? For most projects, shifting from one runtime to another isn't practical if it requires rewriting a significant portion of the code, such as when converting from Node.js to Deno. This is where Bun's major advantage comes into play. Bun natively implements hundreds of Node.js and Web APIs, including fs, path, Buffer, and many more. You can easily install Bun using npm by running:.

npm install bun

npm install bun

And voilà, you're ready to run your project with bun just like that. Simple!

The performance

Bun advertises itself as significantly faster than any other framework, but upon closer inspection, its performance is generally similar to Node.js. For simple, synchronous code that doesn’t demand much memory, Bun outperforms by two to three times. However, when it comes to memory-intensive or asynchronous tasks, its advantage fades. Bun and Node.js deliver nearly identical results for asynchronous tasks. But with memory-demanding tasks, Bun consumes considerably more memory and often takes longer to execute compared to Node.

The catch

Since Bun is just 4 months into its runtime, it has a significant journey ahead. Several issues must be addressed for it to gain wider acceptance among developers.

• Exclusively accessible on MacOS and Linux, there isn't a version that works with Windows. Since Windows is a prevalent choice among developers, this stands out as the most significant drawback.
• Not planning to offer serverless solutions through AWS Lambda or Google Cloud Functions, and this isn't likely to change anytime soon.
• Inadequate documentation. Although it's gradually improving...
• Bugs. It's something that happens with almost every new technology, and this situation is no exception.

Bun’s time will come (probably)

The potential for better performance and easier syntax with Bun is appealing. However, at this stage, I don't find it reasonable to switch from the reliable Node.js. When starting a new project, though, Bun does seem more attractive. There's plenty of room for Bun to grow, and if you're okay with the possibility of significant changes in the technology, it could be an ideal choice. Weighing the advantages and disadvantages, Bun is a fascinating new technology that I'll be monitoring closely. In a few years, it might become a direct competitor to Node.js or even replace it; time will tell.