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A quick comparison of JavaScript and Go executables

Background: Bun and Deno, JavaScript runtimes, provide a native way to convert your JavaScript code into a single executable file.

  • Bun: bun build --compile my-script.js
  • Deno: deno compile my-script.js

To create these executables, Bun and Deno need to include their entire JS runtime in the executable file. That means all of Apple’s JavaScriptCore for Bun and Google’s V8 for Deno. But once that is compiles, the executables should work in any environment that those runtimes support.

I wanted to compare these new JavaScript options and Go to see if JS is a legitimate option for creating cross-environment executables.

Setup: I created a project for a simple command-line utility for reading package.json files from the terminal: Then I implemented the utility in all three environments: Bun, Deno, and Go. I have Bash scripts to create the executables and then compare the results by two metrics: file size and execution time.

The numbers:

File size

  • Bun: 97733752 bytes or 97.7 megabytes
  • Deno: 109968928 bytes or 110.0 megabytes
  • Go: 2607443 bytes or 2.6 megabytes

Go created the smallest executable (by a wide margin). I ran into issues with the Deno executable being rejected by GitHub for being too large, and Bun isn’t far behind.

Execution time

  • Bun: 0:00.04 real, 0.02 user, 0.01 sys
  • Deno: 0:00.04 real, 0.02 user, 0.01 sys
  • Go: 0:00.00 real, 0.00 user, 0.00 sys

The execution time was not a major factor in my example, and my hypothesis is that most of the difference is due to the startup cost of the JavaScript runtime. We would need more tests to determine how big the difference in execution time between these options.

Takeaway: Based on these results, Go is still the superior option for executables based on file size and execution time. However, Bun and Deno provided a great authoring experience for developers who are familiar with the JavaScript ecosystem. And the ability to use pre-existing tools and processes when creating executables might make Bun or Deno the best option for you and your team.

Personally, I’m excited to see how this feature of JavaScript runtimes develops over time.

Afterward: Node.js does have an experimental feature to create executables, but at the time of writing the steps were too involved. For open-source options for creating Node executables, checkout nexe and pkg.