GitHub Copilot is primarily trained on publicly available code , not on one single programming language.

Quick Scoop

The best-supported languages tend to be the ones with the most public code online, especially Python and JavaScript. GitHub’s own materials also describe Copilot as working across a wide range of languages rather than being trained for just one.

What that means

  • It learns patterns from large amounts of public source code and related natural language.
  • It performs especially well in languages with lots of training examples, such as Python, JavaScript, TypeScript, Go, and Ruby.
  • It can still help with many other languages, but suggestion quality can vary depending on how much public code exists for that language.

Simple version

If you want the shortest answer: Copilot was trained mostly on public code from many languages , with stronger coverage in popular languages like Python and JavaScript.