High-Performance Sandbox • Automated Testcase Validation • AI Practice

Free Online Compiler & Problem Solver

Write, compile, and execute code online across 8+ popular programming languages. Test your code against automated test cases, generate customized AI problems, and master competitive programming — zero installation, completely free.

Python 3C++ (GCC)Java (OpenJDK)JavaScript (Node.js)C (GCC)TypeScriptGoRust
Free Online Code Compiler

Welcome to FlareBox Online Compiler. Write, compile, and execute code in Python 3 directly in your browser. No setup, installation, or login required.

Language:Python 3
Version:3.8.1
File Extension:.py
Execution Limit:8.0 Seconds / 256MB
What you can do:
AI Problem Generator
Generate custom coding interview problems with test cases on demand.
Automated Test Case Engine
Check your code against multiple inputs and get instant diff feedback.
Zero Login Required
Free instant compilation for 8+ popular programming languages.
solution.py
Press Ctrl+Enter to run
Loading FlareBox Enterprise Editor...
Terminal Output
Click "Run Code" or press Ctrl+Enter to execute.
Your code will be evaluated against test cases and results will appear here.

Direct Judge0 Sandbox

Lightning-fast code execution running in isolated environments with memory and time benchmarks. Supports standard I/O (stdin and stdout) just like LeetCode and Codeforces.

AI Coding Problem Generator

Generate limitless technical interview questions tailored to any topic (DP, Graphs, Strings) and company target (Amazon, Google, TCS). Includes automated test cases and starter code.

Automated Test Case Checking

Test code against sample test cases and hidden test cases simultaneously. Receive instant diff highlights comparing your actual output with expected output.

Dedicated Online Compilers by Programming Language

Click on any language to open its specialized code runner with syntax guides and cheat sheets.

Python 3
3.8.1
Run Python 3
C++ (GCC)
GCC 9.2.0
Run C++ (GCC)
Java (OpenJDK)
OpenJDK 13.0.1
Run Java (OpenJDK)
JavaScript (Node.js)
Node.js 12.14.0
Run JavaScript (Node.js)
C (GCC)
GCC 9.2.0
Run C (GCC)
TypeScript
3.7.4
Run TypeScript
Go
1.13.5
Run Go
Rust
1.40.0
Run Rust

Frequently Asked Questions

Everything you need to know about using FlareBox Online Compiler & Practice Portal.

Is FlareBox Online Compiler free to use?

Yes, the FlareBox Online Compiler is 100% free with no login required for standard compilation, code running, and custom test case testing.

How does automated test case checking work?

You can define sample or custom test cases with standard input (stdin) and expected output. When you click 'Run Code', our high-performance sandbox compiles and executes your program, comparing stdout against your expected output and displaying pass/fail statuses.

Can I generate AI coding interview problems?

Yes! Simply sign in and click 'Generate AI Problem'. You can customize the topic (e.g. Dynamic Programming, Trees, Arrays), difficulty (Easy, Medium, Hard), or target company (e.g. Amazon, Google, TCS). Free accounts receive 3 AI problems daily, while FlareBox Pro users enjoy unlimited generations.

Which programming languages are supported?

FlareBox supports Python 3, C++ (GCC 9.2), Java (OpenJDK 13), JavaScript (Node.js), C (GCC), TypeScript, Go, and Rust.

Can I test code with custom input (stdin)?

Yes! Switch to the 'Custom Stdin' pane or add custom test cases with specific inputs and outputs to test edge cases, large arrays, and complex inputs.