Do you support deps.edn / additional dependencies?

Not on the free tier — the sandbox has no network egress to pull artifacts. Everything ships with the base install of clojure.

Which JVM version underneath?

A supported LTS JVM — matches what our Java runtime uses.

Can I use ClojureScript?

No — this is JVM Clojure. See /lang/javascript if you want browser-style JS.

Yes — unlimited within your rate-limit tier.

Clojure · online compiler

Run Clojure online

Run Clojure online — Lisp on the JVM, immutable by default. No local install.

Available versions

Clojure 1.11 Clojure 1

Firecracker microVM live per-test verdicts multi-file compile

Clojure is a Lisp that runs on the JVM (also on JS, .NET and BEAM in its cousins). Immutable persistent data structures, first-class functions, macros, and a philosophy of separating identity from state — all backed by the JVM ecosystem.

ls-judge runs Clojure 1.x through the standard clojure launcher inside a Firecracker microVM. Bring a single file, use core, use spec, use whatever you need.

Starter code

What you get in Clojure

Clicking "Run now" opens the playground with this exact code and a matching test case pre-loaded — passes on first Run.

clojure

Clojure 1.11

(let [n (Integer/parseInt (clojure.string/trim (read-line)))] (println (* n 2)))

stdin →

expected →

FAQ

Common questions about Clojure on ls-judge

Do you support deps.edn / additional dependencies?: Not on the free tier — the sandbox has no network egress to pull artifacts. Everything ships with the base install of clojure.
Which JVM version underneath?: A supported LTS JVM — matches what our Java runtime uses.
Can I use ClojureScript?: No — this is JVM Clojure. See /lang/javascript if you want browser-style JS.
Is it free?: Yes — unlimited within your rate-limit tier.