Clojure 1.11.1

Online Clojure Compiler & Editor

Name: myCompiler Clojure
Author: myCompiler

myCompiler is a free online Clojure compiler, editor and code runner that lets you write, run, and share Clojure code directly in your browser. It works as your Clojure 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 Clojure How it works

27+ languages Used by 1M+ developers Free forever

main.clj

(def names ["Alice" "Bob" "Charlie"])

(doseq [name names]
  (println (str "Hello, " name "!")))

(println (str "Count: " (count names)))
(println (str "Sorted: " (sort names)))

Output

Hello, Alice! Hello, Bob! Hello, Charlie! Count: 3 Sorted: ("Alice" "Bob" "Charlie")

How to run Clojure code online

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

Write your code

Open the Clojure 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 Clojure 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 Clojure

A complete online Clojure 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 Clojure interpreter. No downloads, no installations, no environment configuration. Open your browser, go to myCompiler, and start writing Clojure 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 Clojure 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 Clojure 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 Clojure program in seconds.

Open Clojure editor

Clojure on myCompiler

myCompiler runs Clojure 1.11.1, 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 Clojure 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 Clojure editor on your own website.

Use this online Clojure 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 Clojure

Clojure code examples

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

Hello World in Clojure

main.clj

(println "Hello, World!")

Variables and Data Types in Clojure

main.clj

(def name "Alice")
(def age 30)
(def pi 3.14)
(println (str name " is " age " years old"))

If-Else Conditionals in Clojure

main.clj

(let [x 10]
  (cond
    (> x 0) (println "Positive")
    (= x 0) (println "Zero")
    :else   (println "Negative")))

For and While Loops in Clojure

main.clj

(doseq [i (range 1 6)]
  (println (str "Count: " i)))

(let [fruits ["apple" "banana" "cherry"]]
  (doseq [fruit fruits]
    (println fruit)))

Functions in Clojure

main.clj

(defn greet
  ([name] (greet name "Hello"))
  ([name greeting] (str greeting ", " name "!")))

(println (greet "Alice"))
(println (greet "Bob" "Hi"))

Arrays and Collections in Clojure

main.clj

;; Vector
(def fruits ["apple" "banana" "cherry"])
(println (conj fruits "date"))
(println (nth fruits 1))

;; Map
(def person {:name "Alice" :age 30})
(println (:name person))

Records in Clojure

main.clj

;; Clojure uses records
(defrecord Dog [name breed])

(defn bark [dog]
  (str (:name dog) " says Woof!"))

(def rex (->Dog "Rex" "Labrador"))
(println (bark rex))
(println (:breed rex))

Error Handling in Clojure

main.clj

(try
  (/ 10 0)
  (catch ArithmeticException e
    (println "Error:" (.getMessage e)))
  (finally
    (println "Done")))

File I/O in Clojure

main.clj

(import java.io.File)

;; Write to file
(spit "output.txt" "Hello, File!")

;; Read from file
(println (slurp "output.txt"))

Sequences in Clojure

main.clj

(def nums (range 1 11))

;; Lazy sequence operations
(println "Evens:" (filter even? nums))
(println "Squares:" (map #(* % %) (take 5 nums)))
(println "Sum:" (reduce + nums))
(println "First 3:" (take 3 nums))

Try these examples in the editor

How to take input in Clojure online

myCompiler supports standard input (stdin) for Clojure programs. Use Clojure'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.clj stdin supported

(let [name (read-line)
      age (Integer/parseInt (read-line))]
  (println (str "Hello " name "!"))
  (println (str "You'll be " (inc age) " next year.")))

stdin

Alice
25

Output

Hello Alice!
You'll be 26 next year.

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

Start coding now

Getting started with Clojure online

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

If you're new to Clojure, use this online Clojure 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 Clojure 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 Clojure compiler instead of installing one locally?

Feature	myCompiler	Local IDE
Setup time	Instant	Minutes to hours
Installation	None required	Clojure + 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 Clojure?

Clojure is a modern, dynamic, functional programming language that runs on the Java Virtual Machine (JVM). Created by Rich Hickey and first released in 2007, Clojure is a Lisp dialect that emphasizes immutability, functional programming, and interactive development. It provides seamless Java interoperability while offering a completely different programming model.

Clojure's core data structures, lists, vectors, maps, and sets, are all immutable and persistent, sharing structure with previous versions for efficiency. This immutability, combined with software transactional memory (STM) for shared state, makes Clojure exceptionally well-suited for concurrent programming. ClojureScript compiles Clojure to JavaScript, bringing the same model to the browser.

What is Clojure used for?

Clojure is used for data processing and transformation pipelines where immutability prevents data corruption, concurrent systems that need coordinated state management, web development with Ring and Compojure (and ClojureScript on the frontend), financial applications where correctness is paramount, and DSL development leveraging Lisp's macro system. Companies like Nubank (the largest fintech in Latin America) and Walmart Labs use Clojure extensively.

Clojure for beginners

Clojure is not typically recommended as a first language due to its Lisp syntax (parentheses-heavy) and functional paradigm shift. However, learning Clojure transforms how you think about programming, immutability, pure functions, and data transformation become natural. It is ideal for experienced developers who want to deepen their functional programming skills. Use myCompiler's online Clojure compiler to experiment with sequences, higher-order functions, and macros.

Clojure vs other languages

Compared to Haskell, Clojure is dynamically typed and more pragmatic, allowing gradual adoption in JVM ecosystems. Compared to Scala, Clojure is more uniformly functional and simpler but lacks Scala's static type system. Compared to Java, Clojure on the JVM shares the runtime and library ecosystem but offers a completely different, more expressive functional programming model with far less boilerplate.

Why use an online Clojure compiler?

An online Clojure compiler, also called a Clojure REPL or Clojure sandbox, lets you run Clojure code directly in your browser without installing the JVM, Leiningen, or Clojure CLI tools. This is ideal for learning Clojure's Lisp syntax, experimenting with persistent data structures, exploring higher-order functions, and understanding the REPL-driven development workflow.

myCompiler's online Clojure IDE supports the full Clojure standard library including core sequence functions, Java interop, atoms, refs, and agents. Write multi-file Clojure programs, provide stdin input, and save and share your code via URL, completely free.

Why is Clojure so popular?

Clojure has a dedicated, passionate community that prizes simplicity and correctness. Rich Hickey's talks, "Simple Made Easy," "The Value of Values," "Spec-ulation", have influenced programmers far beyond the Clojure community, promoting ideas about immutability and data-oriented design that have entered mainstream programming discourse. Clojure's influence is larger than its market share suggests, as these ideas have permeated functional programming in JavaScript (Immutable.js), Python, and beyond.

Clojure career opportunities

Clojure positions are specialized but well-compensated, Clojure developers consistently rank among the highest-paid in Stack Overflow's salary survey. Roles include backend engineer, data engineer, and full-stack developer at companies like Nubank, Funding Circle, and Cognitect (the company behind Clojure). ClojureScript skills are valued at companies using functional frontend architectures.

Try Clojure 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 Clojure compiler on your website

Add an interactive Clojure compiler to your website, blog, or learning platform. Readers can write and run Clojure 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 Clojure compiler, editor and code runner

HTML

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

Why developers choose myCompiler

A full-featured online IDE for Clojure 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 Clojure compiler, playground, and code runner.

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

myCompiler keeps its Clojure 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.

Yes. Clojure runs on the JVM, so you have access to Java's standard library. You can use Java interop to call Java classes and methods directly from your Clojure code on myCompiler.

Simply open the Clojure 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 Clojure 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 Clojure 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 Clojure 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 Clojure code?

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

Start coding in Clojure

Free · No sign-up required · Clojure 1.11.1