Write, compile, debug and test real Java and Kotlin projects with Maven or Gradle on JDK 8–27, with code completion powered by the Eclipse JDT engine. Open a tab and start coding — there is nothing to install.
A preview of the IDE: a Maven project with a Java file being written with code completion, then run in the console.
Built on the tools Java and Kotlin developers already trust
Completion, navigation, refactoring, tests, a real step debugger and Local History for Java and Kotlin — wired together the way a desktop IDE does it.
Completion, errors as you type, Javadoc on hover, find usages and quick fixes come from the Eclipse JDT language server — the same engine behind Eclipse and VS Code Java — for your sources, the JDK and every Maven or Gradle dependency.
Click the gutter, press Shift+F9 and step with F8 F7. Frames, threads, variables you can edit and watches.
Press Shift twice. Files, classes, symbols and actions with camel-hump matching.
Run one test or a whole class with Ctrl+Shift+F10 and read the results in a tree.
Every save is versioned. Compare with any version and roll back in one click — deleted files too.
Add a dependency from Maven Central and it is downloaded on the next build — with sources, so you can read the library you call.
Pick the version and language level per project in Project Structure — Ctrl+Alt+Shift+S. JDKs are ready on the server.
Create a Kotlin project next to your Java ones. Highlighting, completion, KDoc, Go to Declaration, Find Usages, Rename and Reformat Code work in every .kt file. Press Shift+F10 on fun main() to run it, set breakpoints and run JUnit 5 tests — built with IntelliJ, Maven or Gradle Kotlin DSL.
Shift+F6 renames across the project with a preview of every usage. Generate code with Alt+Insert.
When your build file hasn't changed, Run compiles only what you wrote and starts the program right away.
Bottom sheets, a coding key bar and touch-sized menus — fix a bug from the bus.
No JDK to download, no PATH to fix, no build tool to configure. The server already has everything.
Pick Java or Kotlin, a plain IntelliJ-style, Maven or Gradle project and the JDK it should use. Sample code and JUnit 5 are ready from the first second.
Errors are underlined while you type. Put the caret on one, press Alt+Enter and pick a fix — an import, a missing method or a new class.
Press Run and watch the output stream in. Your program can read what you type, and the same project runs JUnit tests and the debugger.
Homework and labs on any computer — a school laptop, a library PC or a tablet.
Everyone starts with the same JDK and build setup in seconds, not a lesson spent on installs.
Try a library, reproduce a bug or sketch an idea in Java or Kotlin without touching your local setup.
What people usually ask before their first Run.
Yes. Create an account and start coding — no credit card and no trial period.
No. It is an independent web IDE that follows the IntelliJ workflow and shortcuts. Code intelligence comes from the Eclipse JDT language server.
Any JDK from 8 to 27. Each project picks its own JDK and language level in Project Structure (Ctrl+Alt+Shift+S).
Yes. Choose Kotlin in New Project and build with IntelliJ, Maven or Gradle (Kotlin DSL). Completion, KDoc, navigation, Rename, Reformat Code, tests and the debugger work in .kt files, and Kotlin programs run in the same isolated sandbox as Java.
Yes. In IntelliJ and Gradle projects Kotlin code calls your Java classes and Java calls Kotlin. New → Kotlin Class/File and New → Java Class sit side by side in the project menu.
Yes. Declare them in pom.xml, build.gradle or build.gradle.kts — they are downloaded on the next build together with their sources.
Yes. Type into the console while the program runs and press Enter — it arrives on System.in.
No. Programs run as console applications without network ports or windows. Algorithms, libraries, tests and the debugger all work.
Yes. Every Java and Kotlin build and run happens in its own sandbox with memory and disk limits, no access to other projects and no open ports. Programs started with Run have no internet access.
On our servers, with automatic daily backups. Download any project as a .zip archive whenever you like.
Yes. The layout adapts to small screens with bottom sheets, touch-sized menus and a key bar for the symbols you type most.
