I use copilot through VSCode. The copilot plugin lets me either ask questions or ask for edits to my code. I can choose which files to include as an additional context to the prompt. I can additionally choose which model to use. Some models are unlimited, others have some monthly quota. GPT-4o is unlimited and quite good with short tasks.

It has also shortcuts for instance fixing errors in the code by just selecting "fix with copilot". Its a bit hit or miss but for simple things work well.

It is very good and seamless. Cannot think of ever copy pasting multiple files of code to some web chats and back.