Judge0

Judge0 is an open source, sandboxed online code execution system. It exposes an API that compiles and runs code submitted by users or by AI agents, so that products such as competitive programming platforms, e learning sites, candidate assessment tools, online code editors and AI code generation workflows do not have to build their own execution infrastructure. The API supports more than 60 programming languages and accepts additional files alongside a program, custom input, compiler options, command line arguments, and time and memory limits. It returns detailed execution results and can call a webhook when a run finishes. The vendor describes the architecture as scalable and offers it either self hosted or as a managed cloud, with a Python SDK. Judge0 also publishes a free browser based IDE built on the same engine, which can be embedded on other websites, and a mobile IDE for iOS and Android that is listed as coming soon. The core system is free and open source to self host. The hosted service is sold in plans shown in euros and US dollars. The listed tiers are €27, €54 and €107 per month, covering 2,000, 5,000 and 10,000 submissions per day respectively, with extra submissions charged at €0.001 each and community plus email support. The site also lists pay per use and dedicated cloud options.