Online Compiler
Write and run code in 20+ languages right from your browser.
Setting up local development environments with compilers, runtimes, and dependencies can be time-consuming when you just want to test a quick idea or learn a new language.
The Geekflare Online Compiler provides a cloud-based sandbox where you can write and execute code in real-time. With support for over 20 popular languages including Python, JavaScript, Bash, Ruby, Go, Java, C++, and PHP you can run code without installing anything on your device.
Why Use an Online Compiler?
- Zero Setup: Skip the hassle of downloading IDEs, configuring PATH variables, or installing software updates. You only need a web browser and an internet connection.
- Cross-Platform Coding: Write and test code from any device, whether you are on a Chromebook, a tablet, or an office computer.
- Learn: If you want to try out a new language like Go or Rust, you can do so immediately without cluttering your local system with new runtimes.
- Quick Troubleshooting: Paste and debug snippets of code, test algorithms, or run system administration scripts in Bash safely within an isolated environment.
How It Works
Select your programming language from the dropdown menu, type or paste your code into the editor, and click the "Run code" button. The compiler processes your code and displays the output in the console below.
Supported Languages
| Category | Languages |
|---|---|
| Systems | C, C++, Rust, Go |
| JVM | Java, Kotlin, Scala, Groovy |
| .NET | C# |
| Scripting | Python, JavaScript, TypeScript, Ruby, PHP, Perl, Lua, Bash |
| Functional | Haskell |
| Other | Swift, R |
Understanding the Output
The output panel shows one of four states after a run:
- Success — your program finished normally. Standard output is displayed, along with execution time and memory usage.
- Compile error — the source did not compile. The compiler's error message is shown so you can fix the syntax or type errors.
- Runtime error — the program crashed during execution. The stack trace or error message is displayed.
Limits and Constraints
| Limit | Value |
|---|---|
| Source code size | 100,000 characters |
| Standard input size | 10,000 characters |
| CPU time per run | 5 seconds |
| Wall-clock time per run | 10 seconds |
| Network access | Disabled |
These limits protect the shared compute environment and keep results fast for everyone.
Privacy
Your code is sent to our compiler service to execute and gets deleted after the run completes. Drafts you edit in the browser are kept in your browser storage only, they never leave your device unless you click Run.
Frequently Asked Questions
Bash, C, C#, C++, Go, Groovy, Haskell, Java, JavaScript, Kotlin, Lua, Perl, PHP, Python, R, Ruby, Rust, Scala, Swift, and TypeScript. Each runs with a fixed runtime version listed in the language selector.
No. Submitted programs run in an isolated sandbox with network access disabled. They can read from stdin and write to stdout/stderr, but cannot make HTTP requests or open sockets.
Type or paste text into the Standard Input panel before running. Each line is sent to the program's stdin in order.