But and however are often used interchangeably to mean ‘yet’, but they are punctuated differently because however in this context is a conjunctive adverb. Jim lost a fortune gambling, but he still lives in a mansion. Jim lost a fortune gambling; however, he still lives in a mansion. or Jim lost a fortune gambling. However, he still lives in a mansion. But is often regarded as more informal than however. But and however have some distinct meanings. But means ‘on the contrary’ and ‘with the exception that’. I like everyone but her. However can also be used to mean ‘by whatever means, condition or state’. I will get there however I can. The word ‘but’ can be used in the sense of ‘although’. We waited for him for a long time, but he did not turn up. The word ‘however’ can be used in the sense of ‘nevertheless’. The test match, however, continued despite protests from both the teams. Some people think you can’t use but at the beginning of a sentence.

"But" and "however" are synonims. They introduce a sentence which has an opposite meaning from the first sentence. For exemple: I like going with the bike, but only if it's sunny. or I like going with the bike, however when it rains I go with the car. I would say that "however" is more formal, while "but" is used also in the spoken language of everyday life.

i'm not a native English speaker but i will help you as much as possible. (but) you can use it when you have no problem with two things and you choose one for ex: i prefer to eat fish but i ate meat with my friend "it means that you like both fish and meat but you prefer fish" (however) you can use it when you do something you dislike. for ex: i don't like meat however i ate meat with my friend yesterday. i hope this help you .