Deno 1.40.5

Online Deno Editor & Code Runner

Name: myCompiler Deno
Author: myCompiler

myCompiler is a free online Deno editor and code runner that lets you write, run, and share Deno code directly in your browser. It works as your Deno playground, sandbox, fiddle, cloud compiler, and online REPL. No downloads, no installation needed. Just open the editor and start coding with syntax highlighting, autocomplete, and instant output.

Start coding in Deno How it works

27+ languages Used by 1M+ developers Free forever

main.ts

interface Student {
  name: string;
  grades: number[];
}

const students: Student[] = [
  { name: "Alice", grades: [92, 88, 95] },
  { name: "Bob", grades: [78, 85, 90] },
  { name: "Charlie", grades: [95, 92, 98] },
];

const avg = (g: number[]) =>
  g.reduce((a, b) => a + b) / g.length;

for (const s of students) {
  const score = avg(s.grades).toFixed(1);
  console.log(`${s.name}: ${score}`);
}

Output

Alice: 91.7 Bob: 84.3 Charlie: 95.0

How to run Deno code online

Three steps to go from idea to running Deno code in this online playground. No account required.

Write your code

Open the Deno editor and start writing. The smart editor gives you syntax highlighting, autocomplete, and error detection as you type.

Click Run

Hit the Run button or press +Enter to run your Deno code on secure, sandboxed cloud servers.

See results

Output appears instantly in the integrated terminal. Errors and exceptions show up with clear, helpful messages.

Everything you need to code in Deno

A complete online Deno IDE and coding playground in your browser. Write, run, and share code without any setup.

Zero setup required

Start coding in seconds with this browser-based Deno interpreter. No downloads, no installations, no environment configuration. Open your browser, go to myCompiler, and start writing Deno code immediately.

Works on any device with a web browser. Desktop, laptop, tablet, phone, Chromebook. There is nothing to install and nothing to configure.

Feature-rich code editor

Write Deno with a professional-grade code editor built into your browser. Syntax highlighting colors your code for readability, making keywords, strings, and functions easy to distinguish at a glance.

Intelligent autocomplete suggests methods and properties as you type, and real-time error detection catches mistakes before you run your code.

Multi-file projects

Create and manage multiple files in a single project. Use the file sidebar to organize your code into modules, then import them across files just like in a desktop IDE.

Build modular applications with proper project structure. Each file is editable, and you can switch between them instantly.

Run code instantly

Click the Run button or press +Enter to execute your Deno code instantly. This online code runner displays output immediately in the integrated terminal panel. Your code runs on secure, sandboxed cloud servers and results appear in seconds.

Error messages and tracebacks are displayed clearly, making it easy to find and fix issues. The terminal supports ANSI colors for rich output formatting.

Ready to try it? Write and run your first Deno program in seconds.

Open Deno editor

Deno on myCompiler

myCompiler runs Deno 1.40.5, always up to date with the latest stable release. You get a full browser-based IDE with syntax highlighting, intelligent code completion, multi-file project support, a built-in terminal for real-time output, and standard input (stdin) for interactive programs. Write, compile, run, and debug Deno code on any device. Desktop, laptop, tablet, phone, Chromebook. Zero downloads, zero configuration, and no sign-up required. Save your programs with a unique URL and share them with anyone. You can also embed a working Deno editor on your own website.

Use this online Deno playground as a quick code executor for testing snippets, a coding sandbox for learning, or a cloud compiler for coding interview preparation. The editor includes dark mode for comfortable coding, keyboard shortcuts for faster workflows, and clear error messages with line numbers so you can debug quickly. Students use it for homework and practice. Teachers use it to share working examples. Developers use it to prototype ideas. myCompiler is beginner-friendly, fast, and completely free. It works in any modern web browser.

Start coding in Deno

Deno code examples

Common Deno patterns you can try in the online compiler. Each example is ready to run.

Hello World in Deno

main.ts

console.log("Hello, World!");

Variables and Data Types in Deno

main.ts

const name: string = "Alice";
let age: number = 30;
const isStudent: boolean = true;
console.log(`${name} is ${age} years old`);

If-Else Conditionals in Deno

main.ts

const x = 10;
if (x > 0) {
  console.log("Positive");
} else if (x === 0) {
  console.log("Zero");
} else {
  console.log("Negative");
}

For and While Loops in Deno

main.ts

for (let i = 0; i < 5; i++) {
  console.log(`Count: ${i}`);
}

const fruits = ["apple", "banana", "cherry"];
for (const fruit of fruits) {
  console.log(fruit);
}

Functions in Deno

main.ts

function greet(name: string, greeting = "Hello"): string {
  return `${greeting}, ${name}!`;
}

console.log(greet("Alice"));
console.log(greet("Bob", "Hi"));

Arrays and Collections in Deno

main.ts

const fruits = ["apple", "banana", "cherry"];
fruits.push("date");
console.log(fruits[1]);

const person = { name: "Alice", age: 30 };
console.log(person.name);

Classes and Objects in Deno

main.ts

class Dog {
  constructor(public name: string, public breed: string) {}

  bark(): string {
    return `${this.name} says Woof!`;
  }
}

const dog = new Dog("Rex", "Labrador");
console.log(dog.bark());

Error Handling in Deno

main.ts

try {
  const result = JSON.parse("invalid json");
} catch (e) {
  console.log(`Error: ${(e as Error).message}`);
} finally {
  console.log("Done");
}

File I/O in Deno

main.ts

// Write to file
await Deno.writeTextFile("output.txt", "Hello, File!");

// Read from file
const content = await Deno.readTextFile("output.txt");
console.log(content);

Fetch API in Deno

main.ts

// Top-level await and TypeScript generics
const encoder = new TextEncoder();
const data = encoder.encode("Hello, Deno!");
await Deno.writeFile("output.txt", data);

const content = await Deno.readTextFile("output.txt");
console.log("File content:", content);
console.log("Bytes written:", data.length);

Try these examples in the editor

How to take input in Deno online

myCompiler supports standard input (stdin) for Deno programs. Use Deno's standard input functions to read user input. Enter your input data in the stdin panel before running your program.

This works for both single-line and multi-line input. You can read strings and convert to numbers using the language's built-in I/O functions.

Try it yourself

main.ts stdin supported

const decoder = new TextDecoder();
const buf = new Uint8Array(1024);
const n = await Deno.stdin.read(buf);
const input = decoder.decode(buf.subarray(0, n!)).trim();
const [name, age] = input.split("\n");

console.log(`Hello ${name}!`);
console.log(`You'll be ${+age + 1} next year.`);

stdin

Alice
25

Output

Hello Alice!
You'll be 26 next year.

No setup, no sign-up. Start writing Deno code right now.

Start coding now

Getting started with Deno online

You can start writing and running Deno code right now without installing anything. Type your code, and click Run. This free Deno code runner executes your program instantly and displays the output in the terminal panel below the editor. Open the Deno online editor, type your code, and click Run.

If you're new to Deno, use this online Deno playground to start with the basics like variables, data types, conditionals, and loops. The code examples above cover all the fundamentals you need to get started. Each example can be copied into the sandbox and run immediately. No setup, no configuration.

As you progress, try creating multi-file projects, using libraries, and sharing your programs with others via URL. Sign up for a free account to save your work and build a personal library of programs. myCompiler works as a full online Deno IDE right in your browser.

Who uses myCompiler

Whether you're learning to code, preparing for interviews, or prototyping ideas, myCompiler is built for you.

Students & Learners

Practice exercises, complete homework assignments, and experiment with code without installing anything on school or personal computers.

Teachers & Educators

Share code examples with students via unique URLs. Embed the compiler in course materials so students can run examples directly in the browser.

Interview Candidates

Practice coding interview problems, test algorithms, and verify solutions quickly during preparation for technical interviews.

Professional Developers

Quickly prototype ideas, test code snippets, or try out a library without setting up a local environment. Great for quick experiments.

Content Creators & Bloggers

Embed interactive examples in blog posts, tutorials, and documentation so readers can run code without leaving the page.

Teams & Collaborators

Share code snippets with colleagues via URLs. Others can view, run, and fork your code to build on your work.

myCompiler vs. local IDE

Why use an online Deno compiler instead of installing one locally?

Feature	myCompiler	Local IDE
Setup time	Instant	Minutes to hours
Installation	None required	Deno + IDE required
Device support	Any browser	Desktop only
Sharing code	One-click URL	Manual (file, git, etc.)
Languages	27+ in one place	One at a time
Cost	Free forever	Free to $$$
Works on Chromebook	Yes	Limited

What is Deno?

Deno is a modern, secure runtime for JavaScript and TypeScript built on the V8 engine and written in Rust. Created by Ryan Dahl, who also created Node.js, Deno was first released in 2020 and was designed to fix architectural shortcomings in Node.js, including module security and the lack of native TypeScript support.

Deno ships as a single executable with no node_modules folder and no package.json. It uses URL-based imports for third-party modules, has a built-in standard library, and supports top-level await out of the box, making it a cleaner, more modern alternative to Node.js.

What is Deno used for?

Deno is used for server-side web applications with frameworks like Fresh and Oak, command-line tools and scripts, serverless functions via Deno Deploy, TypeScript execution without a build step, and WebAssembly workloads. Its built-in formatter, linter, and test runner make it a complete development environment out of the box.

Deno for beginners

Deno is a solid choice for developers already familiar with JavaScript or TypeScript who want a cleaner, more secure runtime. Its built-in TypeScript support means no tsconfig.json setup is needed. The permission model, where you explicitly grant access to files, network, and environment, teaches good security habits from the start. Use myCompiler's online Deno editor to try Deno without installing anything on your machine.

Deno vs other languages

Compared to Node.js, Deno has native TypeScript support, a secure-by-default permission model, and no node_modules, but Node has a far larger package ecosystem (npm). Compared to Bun, Deno has stronger security guarantees and a more mature standard library, while Bun focuses on maximum performance and npm compatibility. The choice between Deno and Node.js mostly comes down to whether you prefer a modern opinionated runtime or the vast existing npm ecosystem.

Why use an online Deno compiler?

An online Deno editor, also called a Deno playground or sandbox, lets you run Deno and TypeScript code directly in your browser without installing the Deno runtime locally. This is useful for experimenting with Deno's APIs, testing scripts, learning TypeScript without configuration, and sharing reproducible code examples with teammates or in forum posts.

myCompiler's online Deno editor supports the full Deno standard library, TypeScript compilation, and standard input/output. You can save your Deno scripts, share them via URL, or embed them in documentation, completely free with no sign-up required.

Why is Deno so popular?

Deno has gained traction for its modern developer experience: native TypeScript, built-in tooling (fmt, lint, test, doc), and a secure permission model that many developers consider a significant improvement over Node.js. Deno Deploy, a globally distributed serverless platform, has further boosted adoption. While it is younger than Node.js, its clean design and active development make it increasingly popular for new projects and microservices.

Deno career opportunities

Deno knowledge is valued in roles involving TypeScript development, serverless architectures, and full-stack JavaScript engineering. As Deno Deploy and the Deno ecosystem mature, demand for Deno-proficient developers is growing, especially in companies adopting modern JavaScript runtimes and edge computing platforms.

Try Deno online Free · No sign-up needed

Keyboard shortcuts

Code faster with these keyboard shortcuts in the myCompiler editor.

Run code

+ Enter

Save program

+ S

Toggle comment

+ /

Indent line

Tab

Unindent line

Shift + Tab

Undo

+ Z

Select next occurrence

+ D

Find & replace

+ H

Embed the Deno compiler on your website

Add an interactive Deno compiler to your website, blog, or learning platform. Readers can write and run Deno code directly on your page without leaving it.

Perfect for technical tutorials, coding courses, documentation, and educational content. Save a program on myCompiler and use the embed link to add it to any webpage.

Embedded Deno editor and code runner

HTML

<iframe
src="https://www.mycompiler.io
    /embed/deno"
width="100%"
height="400"
frameborder="0">
</iframe>

Why developers choose myCompiler

A full-featured online IDE for Deno and 27+ other programming languages.

27+ Languages

Python, JavaScript, Java, C++, Rust, Go, TypeScript, C#, and many more. All compilers and interpreters in one place. Switch languages instantly.

Dark & Light Mode

Switch between light and dark themes with one click. Code comfortably in any lighting condition, day or night.

Mobile Friendly

Fully responsive editor optimized for phones, tablets, and Chromebooks. Code on any device with a web browser. No app download needed.

Save & Share Code

Save programs to your account, share via unique URLs, and let others view, fork, and run your code. Great for collaboration and code reviews.

Tags & Organization

Organize your saved programs with tags and find them quickly with search and filters. Build a personal library of code snippets and solutions.

No Account Required

Start writing and running code immediately. No sign-up, no email, no credit card. Create a free account later only if you want to save your work.

Explore more programming languages

myCompiler supports 27+ languages. Switch between them anytime. All free, all in one place.

View all 27+ languages

Frequently asked questions

Common questions about using the online Deno compiler, playground, and code runner.

Yes! myCompiler is completely free for all supported languages including Deno. There are no subscriptions, no premium tiers, and no hidden costs. Every feature is available at no charge.

myCompiler keeps its Deno environment up to date. You can see the exact version on the language details section of this page. We regularly update all language runtimes to their latest stable versions.

Deno is a modern JavaScript/TypeScript runtime with built-in TypeScript support and a secure-by-default permission model. On myCompiler, you can write and run Deno code with the same ease as Node.js.

Simply open the Deno editor, write or paste your code, and click the Run button. Your code will be executed on our servers and the output will appear in the terminal panel within seconds.

Yes. Click Save to store your program. You will receive a unique URL that you can share with anyone. Recipients can view, fork, and run your code.

Yes. myCompiler supports multi-file projects. You can create, rename, and delete files in the sidebar. This lets you organize your Deno code just like in a local IDE.

Yes. All code runs in isolated containers on our servers. Each execution gets its own sandboxed environment that is destroyed after completion. Your code cannot affect other users or our infrastructure.

Yes. myCompiler has a responsive design optimized for phones and tablets. You can write and run Deno code on the go. The mobile interface uses tabs for switching between the editor, output, and file panels.

Yes. Click the Input tab in the bottom panel, type or paste your input data, then click Run. Your program will read from the input you provided.

Execution is fast. Code runs on our optimized cloud infrastructure and output typically appears within seconds. Execution time depends on the complexity of your program.

Yes. myCompiler provides an embed feature. You can copy an iframe snippet and paste it into your website, blog, or documentation. Visitors can edit and run code directly on your page.

myCompiler supports common editor shortcuts including Run (Ctrl/Cmd+Enter), Save (Ctrl/Cmd+S), Find (Ctrl/Cmd+F), and more. See the keyboard shortcuts section on this page for the full list.

No. myCompiler requires an internet connection because code is compiled and executed on our cloud servers. The editor itself loads in your browser, but running code requires connectivity.

myCompiler offers a fast, free, zero-setup environment with a modern code editor, multi-file support, dark mode, and instant sharing. It is ideal for learning, prototyping, interviews, and sharing code examples.

Yes. myCompiler is great for practicing algorithms and coding problems. You can write Deno code, provide custom input, and test your solutions instantly. Save your work and come back to it anytime.

Use print statements or console output to trace your program's behavior. myCompiler shows all standard output and error messages in the terminal panel. Error messages include line numbers to help you locate issues.

Ready to write Deno code?

Open the free Deno playground and start coding immediately. No downloads, no account required.

Start coding in Deno

Free · No sign-up required · Deno 1.40.5