Write real code, run it right here
The sandboxes are real compilers and runtimes: no sign-up, no account, nothing saved anywhere but your own browser. Share what you build with a link.
Sandboxes
Java sandbox
Java 8 to 25Real JVMJUnit 5
Write and run real Java: packages, Scanner input, records, sealed types and pattern matching, JUnit 5 tests, with live error checking as you type.
Python sandbox
Python 3.12numpy, pandas & moreMulti-file
Write and run real Python: modules and packages, input(), classes, f-strings, the standard library plus numpy, pandas, sympy and more, with live syntax checking.
JavaScript sandbox
Runs in your browserNode-styleMulti-file
Write and run real JavaScript: import/export and require between files, async/await, input from the terminal, with live syntax checking. Nothing leaves your browser.
TypeScript sandbox
Runs in your browserType-checkedMulti-file
Write and run real TypeScript: interfaces, generics and modules, type errors flagged as you type, then compiled and run without leaving your browser.