📖 Complete Guide

How to Use
Acubens Compiler

Step-by-step instructions to compile and run C, C++, Java, Python, HTML and SQL code online for free.

Table of Contents

Getting Started — Quick 5 Steps
Supported Languages & Compilers
Using the Code Editor
Handling User Input
Keyboard Shortcuts
Understanding Error Messages
Language-Specific Tips
Frequently Asked Questions

1. Getting Started — Quick 5 Steps

Choose Your Language

Go to acubens.in/compilers and click on your language: C, C++, Java, Python, HTML or SQL.

Write or Paste Your Code

Type your code in the left editor panel. Load an example from the Examples dropdown.

Click Run

Click ▶ Run or press Ctrl+Enter. Your code compiles and executes instantly.

See Output

Your program output appears in the terminal on the right. Errors are shown in red.

Provide Input if Needed

If your program uses scanf, Scanner or input(), the terminal becomes interactive — type and press Enter.

2. Supported Languages & Compilers

Language	Compiler / Runtime	Standard	Best For
C	GCC	C17	Systems programming, BCA/B.Tech practicals
C++	G++	C++17	OOP, competitive programming, STL
Java	JDK 17	Java 17	OOP, enterprise, MCA projects
Python	CPython 3.11	Python 3.11	Data science, scripting, automation
HTML/CSS/JS	Browser (live)	HTML5/ES6+	Web development, UI design
SQL	SQLite (WASM)	SQLite 3	Database queries, SQL practice

3. Using the Code Editor

Line numbers are shown on the left for easy reference
Press Tab to insert 4-space indentation automatically
Use Ctrl+Z to undo, Ctrl+A to select all
Use the Examples dropdown to load ready-made code samples
Drag the divider bar between editor and output to resize panels

💡 Pro Tip

Press Ctrl+Enter to run your code instantly without clicking the Run button.

4. Handling User Input

Acubens supports interactive input. When your program waits for input, the terminal activates and you can type directly.

C — scanf()

#include <stdio.h> int main() { int a, b; printf("Enter two numbers: "); scanf("%d %d", &a, &b); printf("Sum = %d ", a + b); return 0; }

Python — input()

name = input("Enter your name: ") print(f"Hello, {name}!")

⚠ Important

When your program is waiting for input, click on the terminal area and type, then press Enter.

5. Keyboard Shortcuts

Shortcut	Action
`Ctrl`+`Enter`	Compile and Run code
`Tab`	Insert 4-space indentation
`Ctrl`+`Z`	Undo last edit
`Ctrl`+`A`	Select all code
`Enter` in terminal	Submit input to running program

6. Understanding Error Messages

Compile Error — Syntax mistake. Read the error line number and fix it.
Runtime Error — Code compiled but crashed while running.
Timed Out — Program ran more than 30 seconds. Check for infinite loops.
exit 0 — Program completed successfully.

7. Language-Specific Tips

Java: Always use public class Main. Acubens handles renaming automatically.
Python: Uses Python 3.11 with -u flag — print() output appears instantly.
HTML: All three tabs (HTML, CSS, JS) are combined and previewed live.
SQL: Sample tables are pre-loaded. SELECT, INSERT, UPDATE, DELETE and CREATE TABLE all work.

8. Frequently Asked Questions

Is Acubens compiler free?

Yes, 100% free. No signup, no subscription, no hidden charges. Free for everyone in Bihar and India.

Do I need to install anything?

No. Just open your browser and go to acubens.in/compilers. Works on Chrome, Firefox, Edge and mobile browsers.

Can I use it on mobile?

Yes! Acubens is fully mobile-responsive. Works on Android and iOS smartphones.

Which Java class name should I use?

Always use public class Main. Acubens automatically renames your class to Main during compilation.

Start Coding Now →

How to UseAcubens Compiler