GPT-4 is significantly better, especially when it comes to story translations. Did a test on Japanese visual novel text, comparing human, gpt-4, google, and deepl translations, and it's scarily good, enough to change the translation industry type of good.

Edit: If you're on mobile and you can't see the GPT 4 translation, swipe left, it's a table.

I've tried using Bing Chat for translations before and it's done worse compared to GPT-4 based on my experience. There's a theory that it uses Bing translate instead of GPT-4, though I don't know how true that is.

It sometimes rejects translations as well, which I found pretty odd. Maybe it's because of the prompt? I actually did a comparison test on this on Japanese visual novel text, Humans vs GPT-4 vs Google Translate vs DeepL on this post. Most still prefer the human translation on that post, but I also did a blind test poll to see which one they think is better, and the human actually only won by 5 votes.

Edit: If you're on mobile and you can't see the GPT 4 translation, swipe left, it's a table.