Online Scala Compiler
Write Scala in the browser and run it on our machines. The editor is opening.
Free online Scala compiler and editor
JDoodle is an online IDE that has served the programming community since 2013. You write, compile, and run code in the browser for Scala and many other languages, without installing a toolchain.
What you see on this page is JDoodle’s free Scala compiler. Write Scala in the editor, press Execute, and JDoodle runs it on its servers. You do not install Scala, and you do not need a JDoodle account to run code.
Online Scala editor
JDoodle’s Scala editor on this page highlights syntax, completes as you type, matches brackets, and folds blocks. It is an online Scala editor and a compiler together: you write here, then Execute runs your program on JDoodle’s servers.
Scala versions on JDoodle
JDoodle currently ships these Scala builds. Choose one from the version menu before you execute. The installed releases are 2.12.0, 2.12.4, 2.12.5, 2.13.0, 2.13.6, 2.13.12, and 2.13.16.
| Version |
|---|
| 2.12.0 |
| 2.12.4 |
| 2.12.5 |
| 2.13.0 |
| 2.13.6 |
| 2.13.12 |
| 2.13.16 |
Maven libraries
JDoodle can pull public Maven packages into a Scala run. Add them in the library field, for example org.apache.commons:commons-lang3:3.4. Look up packages on search.maven.org. Private or local packages are not available on this JDoodle page.
Debugging Scala online
JDoodle debugs Scala in the browser, so you do not have to read a program and guess what it did. Set a breakpoint by clicking a line number, press Debug, and execution stops there. From that point you can step over a line, step into a call, step back out, or let it run on to the next breakpoint, and the call stack beside the editor shows how you arrived. Every local variable in the frame you are looking at is listed with its current value, and objects and arrays open up so you can look inside them. A debug session is interactive, so a program that reads input still reads it from you while it is paused.
Debugging runs on 2.13.16, the newest Scala build here and the one this page opens with. Older versions still compile and run as they always did, and the Debugger tab says so if you switch to one.
Debugging is free to use. Sessions last three minutes on the free plan and ten minutes on Pro and Teacher plans, and you can start as many as you need.
Frequently asked questions
Is JDoodle’s online Scala compiler free?
Yes. JDoodle lets you write and run Scala without paying. A JDoodle account is only needed to save projects, use more AI credits, or unlock faster workspaces.
Do I need to install Scala to use JDoodle?
No. JDoodle runs Scala on its servers. Open this page in a browser and execute.
Which Scala version should I pick on JDoodle?
Choose the version that matches the course or codebase you are working against from the version menu. The builds JDoodle has installed are 2.12.0, 2.12.4, 2.12.5, 2.13.0, 2.13.6, 2.13.12, and 2.13.16.
Can I add Maven libraries on JDoodle?
Yes, if the package is public. Private or local packages are not supported on this JDoodle page.
Can I run a multi-file Scala project online?
Not on this page, which runs a single Scala file. For several files in one project, open the JDoodle Scala IDE. Everything else works the same on both.
Is this an online Scala editor or a compiler?
Both. The page is an online Scala editor and it compiles and runs what you write.
Can I debug Scala code online?
Yes. JDoodle has a step debugger for Scala. Click a line number to set a breakpoint, press Debug, and the program stops there so you can step over, step into, and read the call stack. Local variables are listed with their values while you are paused, and you can open objects and arrays to look inside. Debugging runs on 2.13.16, the newest build here and the one this page opens with. Debugging is free, and a session runs for three minutes on the free plan or ten on a paid one.
Input, interactive runs, files, and the rest of the editor work the same on every language. See the JDoodle IDE documentation.