Codeground AI

Kotlin Online Compiler

Write Kotlin, press Run, read stdout. JVM Kotlin in a sandbox — nothing to install locally.

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About this editor

Write Kotlin, press Run, read stdout. JVM Kotlin in a sandbox — nothing to install locally.

Practice Kotlin syntax, collections, and small programs before Android or backend work. Compile and run in one click.

Key features

Kotlin runs server-side

kotlinc compiles to a JAR, then the JVM runs it in a sandbox.

One-click Run

Output, stderr, and compiler errors land in the panel below. No local install.

VS Code–like editor

Syntax highlighting, bracket matching, and shortcuts that feel familiar if you use VS Code.

Shareable links

Save with a title and copy the URL — handy for reviews, homework, or interview screens.

No setup

Open the page and start typing. Account optional for basic runs.

Room to grow

Need multiple files? Open a cloud workspace from the top bar.

Getting started

  1. 1
    Write your code

    Type or paste Kotlin in the editor. A starter template is there if you want to run something immediately.

  2. 2
    Press Run

    Check the output panel underneath for results or errors.

  3. 3
    Edit and rerun

    Change a line, run again. Most people loop here until the output looks right.

  4. 4
    Save for a permalink

    Add a title when you save. You get a link you can send to a teammate or drop in a doc.

  5. 5
    Bigger project?

    Cloud workspaces handle multi-file repos and longer sessions. Link is in the top nav.

Common questions

Is this Kotlin compiler free?

Yes. No payment and no account required for a quick run. Sign in if you want saves tied to your profile.

Do I need to install anything?

No. Code runs on Codeground servers in a sandbox. Just open the page.

What Kotlin version runs here?

Modern Kotlin compiler on the JVM in a sandbox.

Can I share my code?

Save with a title to get a permalink, or share the playground URL as-is.

Works for interviews?

Yes. Share a ground link, or use interview mode for a live shared editor.

Multiple files?

This page is for single-file snippets. Use a cloud workspace for full projects.

Will my code still be here tomorrow?

Anonymous sessions can reset. Save with a title (and sign in) for a stable link.

Why use this instead of installing locally?

Good for quick tests, learning, and sharing a snippet. For large offline work, a local IDE still wins.

Is this an online Kotlin IDE or playground?

A browser playground with syntax highlighting and one-click Run — run Kotlin online without a full local install. Cloud workspaces cover multi-file projects.

Is there a free Kotlin playground?

Yes. Compile and run Kotlin online for free—no Android Studio or local JDK required for snippets.