I'm surprised that nobody on HN seems to point to or mention bing chat. It is based on GPT, it is much better than free GPT 3.5 and it is free as well. I use it plenty of times and more than 90 percent of the time answers are exact and code just works as is. You just ask it extra questions about how it works and it explains it in as much detail as you possibly need, until you fully understand. Then you ask it to rewrite it this or that way and you try it out and add features step by step. Works like a charm.