GitHub Copilot vs ChatGPT for Coding Tests

GitHub Copilot and ChatGPT both write code, but they sit at different points in the workflow. Copilot lives in your IDE and completes lines as you type. ChatGPT lives in a chat window and writes whole functions on request. For coding-test scenarios, the trade-off matters.

Copilot integrates into VS Code, JetBrains, and a handful of other IDEs as a real-time autocomplete. It uses a fine-tuned OpenAI model to produce inline suggestions. ChatGPT is the general-purpose chat product. For coding tests where you can use any tools, Copilot in your IDE is the smoothest experience. For tests delivered through a locked browser (HackerRank, Codility-with-proctoring, university CS exam), Copilot likely cannot run; ChatGPT through the overlay is more flexible. Both can read and explain code; only Copilot suggests inline as you type.

They detect known IDE plugins by name. Most academic proctors do not allow IDEs anyway; you take the exam in their secure browser.

GPT-4o solves easy/medium LeetCode reliably. Hard problems still trip it. Copilot is similar - it produces a first draft you must verify.

For exams you cannot use AI in, yes. For real work, Copilot fills in syntax for you most of the time.