Bun Online Compiler
Write and run JavaScript and TypeScript online using the Bun runtime directly from your browser. This free Online Bun Compiler lets you test modern JS/TS code quickly without installing Bun, Node.js, package managers, or configuring a local development environment.
How to Use This Bun Compiler
- Write your JavaScript or TypeScript code
Enter or paste your code into the Code Editor. You can test standard JavaScript syntax as well as TypeScript features supported by the Bun runtime. - Click the Run button
Select Run to execute your code with Bun. If the program contains a syntax or runtime error, review the returned message and update your code. - Check the Output screen
Program results, logs, or errors appear in the Output panel. Use the available controls to copy, download, or delete the output before your next test.
Key Features
- JavaScript and TypeScript Execution: Run both JavaScript and TypeScript code using the Bun runtime.
- Native TypeScript Support: Test TypeScript directly without manually compiling it to JavaScript first for supported use cases.
- Zero Installation: No need to install Bun, Node.js, TypeScript, or configure a local runtime just to test code.
- Instant Execution: Click Run and view your program output or runtime errors immediately.
- Dark and Light Mode: Switch the Code Editor theme to suit your preferred coding environment.
- Modern JavaScript Support: Experiment with variables, functions, classes, async code, promises, arrays, objects, and other supported modern JavaScript features.
- Bun Runtime Testing: Useful for experimenting with Bun-specific functionality when the required API is available in the online execution environment.
- Output Controls: Copy, download, or clear generated output directly from the Output panel.
1. Does this online Bun compiler support TypeScript directly?
Yes. Bun is designed to execute TypeScript files directly, so you can test supported TypeScript syntax without running a separate manual transpilation step first.
Enter the code in the Code Editor, click Run, and check the result in the Output screen.
2. Can I use Bun-specific APIs such as Bun.version?
Bun-specific APIs can be used when they are exposed by the runtime and permitted by this online execution environment. For example, you can try:
If a particular Bun API requires filesystem access, networking, external processes, or another restricted capability, it may not behave the same way as it would in a full local Bun installation.
3. How is Bun different from Node.js in this online environment?
Both Bun and Node.js can execute JavaScript outside the browser, but Bun provides its own runtime and includes built-in support for features such as direct TypeScript execution.
On this page, your code is executed with the Bun runtime, so Bun-specific behavior or APIs may differ from equivalent Node.js programs. Code that depends on Node.js-specific packages or system functionality may require adjustments.
4. Do I need to install Bun or TypeScript on my computer?
No. You can use this Bun Online Compiler directly in your browser without installing Bun, TypeScript, Node.js, or another local development tool.
A local Bun installation may still be preferable for full application development, package management, filesystem-heavy projects, servers, or features that require unrestricted access to your operating system.