Free online compiler

Write a program, add input if it needs any, and press Run. Nothing to install, no account and no API key.

How each language runs

• Python: runs inside your browser, so your code stays on your device. The engine starts loading as soon as the page opens, so your first run is usually quick. Common packages such as numpy load automatically when imported.
• JavaScript: runs in your browser in an isolated worker. Output comes from console.log. Read input with input(), which returns the next line of stdin.
• C, C++, Java, C#, Kotlin, Go, Rust and Ruby: compiled and run on a remote server with time and memory limits, so your code is sent to that server. If one server is busy, the tool automatically retries and tries a backup. Java and Kotlin code must use Main as the class name.

Use Share to copy a link that contains your code, and Download to save it as a file. Need to build a web page instead? Try the HTML, CSS & JS studio.