Judge0 CE is an open-source online code execution system designed to compile and run untrusted code securely in a sandboxed environment. It exposes a simple HTTP JSON API, making it suitable for building products that need reliable, scalable code execution for both human users and AI-generated code.

Key Features

Sandboxed compilation and execution of untrusted code
HTTP JSON API designed for straightforward integration
Supports a large catalog of programming languages (commonly 60+; community deployments may support more)
Scalable architecture intended for high-throughput workloads
Detailed execution results (stdout/stderr, exit status, resource usage)
Configurable limits (time, memory) and runtime options (arguments, compiler flags)
Multi-file and “project-style” submissions with additional files support
Webhooks (HTTP callbacks) for asynchronous workflows

Use Cases

Online IDEs, code runners, and browser-based programming editors
Competitive programming and automated evaluation platforms
E-learning, coding assignments, and training environments

Limitations and Considerations

Running arbitrary code requires careful operational hardening and resource isolation; correct sandbox configuration is essential
Supported languages and toolchains depend on the chosen Judge0 flavor and installed runtime images

Judge0 CE provides a pragmatic foundation for secure remote code execution, emphasizing API-first integration and scalable processing. It is commonly used as a backend component for education platforms, assessments, and AI workflows that need to safely execute generated code.