Online Compiler — Run Code in Your Browser
Write and run Python, JavaScript, C++, Java, and 6 more languages instantly. No installation, no account, free forever.
Start Coding NowFree · Instant · 10 languages · No installation needed
Supported Programming Languages
Data science, AI, automation, beginners
Web development, Node.js, scripting
Systems, competitive programming, games
Enterprise apps, Android, academics
Systems programming, embedded, OS
Cloud services, APIs, concurrency
Systems, performance-critical code
Web backends, WordPress, scripting
Web apps, scripting, Rails
Typed JavaScript, large-scale apps
How to Use the Online Compiler
Choose Language & Write Code
Select your language from the dropdown. Write or paste your code in the editor. Example programs are available for each language.
Add Input if Needed
If your program uses cin, scanf, or input(), the Program Input panel opens automatically. Enter each input value on a new line.
Run and See Output
Click Run or press Ctrl+Enter. Output appears in under 2 seconds. Errors include beginner-friendly hints to help you fix them.
Frequently Asked Questions
Is this online compiler free?
Yes. The ToolForge Online Compiler is completely free with no usage limits for normal use. No account, no signup, no credit card required.
Which programming languages does it support?
The compiler supports Python 3, JavaScript (Node.js), C++, Java, C, Go, Rust, PHP, Ruby, and TypeScript — 10 languages total. More may be added in the future.
Can I run code that asks for user input?
Yes. Click the "Program Input" panel below the editor and enter your values before running. Enter each value on a separate line. For example, if your program asks for two numbers, type the first number, press Enter, then type the second number.
How fast is the code execution?
Most programs run in under 2 seconds. The compiler uses Judge0 CE, a production-grade sandboxed execution environment. Complex programs or those with heavy computation may take slightly longer.
Is my code safe and private?
Your code is sent to Judge0's sandboxed servers for execution only. ToolForge does not store, log, or analyze your code in any way. The execution environment is completely isolated.
What is the maximum execution time?
Programs are automatically terminated after 10 seconds to prevent infinite loops or runaway processes. If your program times out, simplify your code or check for infinite loops.
Can I use this for competitive programming?
Yes. The compiler is suitable for practicing competitive programming problems in C++, Python, Java, and other supported languages. The execution environment mirrors standard online judge settings.
Why does my Java class need to be named Main?
The Judge0 execution environment expects the main Java class to be named exactly "Main" (case-sensitive). This is a constraint of the sandboxed environment, not standard Java. Make sure your class declaration reads: public class Main { ... }
Start Coding Right Now
No installation. No signup. Just code.
Open Online Compiler