Hackerearth vs Judge0 CE

HackerEarth's v4 Code Evaluation API lets registered client applications submit source code in dozens of languages for asynchronous sandboxed compilation and execution, returning results via a callback URL rather than a blocking response. Every call must carry a client-secret issued after registering a web application, confirmed live by a real request that failed with "client_secret is needed!" rather than any generic error. HackerEarth's own docs describe a cap on both the number of registered clients and the number of free requests per account, with no public self-serve pricing page — consistent with a freemium model gated behind manual registration rather than an open paid tier.

Judge0 CE is an open-source sandboxed code-execution engine, and ce.judge0.com is its free public demo instance covering 60-plus compiler/language versions via a REST API for creating and polling submissions. A live, fully unauthenticated request — no token, no key — both listed supported languages and executed a real Python submission end-to-end, confirming the public instance ships with authentication disabled by default. Judge0's own docs steer production users toward a paid RapidAPI-hosted plan or self-hosting instead, but the tracked ce.judge0.com endpoint itself remains free to call directly.