無料で使用できるDeepLの翻訳精度はかなり高い様です。一部敬語などを修正するだけで人間の翻訳に近いそうです。The translation accuracy of DeepL, which is free to use, seems to be quite high. It is said that it is close to a human translation by only modifying some honorifics and so on.

https://www.deepl.com/ja/translator