Thanks. You got it

Can "You got it, dude " be used as a reply to "thank you" in informal English?

The purpose of informal language is to communicate. There are no formal rules for informal communication. If you want to say that, you can. As long as it gets the message across.

Now, if you wanted to use that formally, then no. It makes no sense. But informal language often doesn't "make sense".

Yes, in the US “you got it!” is used as an informal reply to “thank you”. Even though it may sound a bit confusing, as the last commentator pointed out, the meaning behind it is similar to “sure thing” or “any time”. It is not a simple “you’re welcome” but more so “you are always welcome”, i.e. every time you need my help you will get it, it’s no bother.

In any case it is extremely informal and even in the US if you are working or are in a more formal environment you may want to stay away from it, because to a complete stranger it may come off as if your response is not genuine or is being too familiar. Between strangers “You are welcome” or “It is my pleasure” is a much more polite and appreciated response. Plus you would sound more educated.

Also it depends on situation. If you are a waiter and every time you bring something to someone’s table they may say a quick “thanks” to which you can reply “you got it”, because you are likely to have to bring more things to their table and it’s part of your job. But if you hold the elevator for someone for a full minute, they are more likely to express a more explicit gratitude like “thank you so much!”, to which it is nicer to respond with “my pleasure” or “you are very welcome!”

Confirmation or acknolwedgement?

To me, "you got it!" is primarily a confirmation of a request, not an acknowledgement of thanks.

The use of "thanks" in sentences that are actually requests ("e.g., I'll have a regular coffee, thanks") might make this unclear, but as a response to a simple statement of thanks, "you got it!" doesn't sound natural. My first thought is, "got what? I didn't ask for anything"

On the other hand, a more complete phrase, "Anything [you want], you got it" does fit as a response to "thank you", as it's saying that the speaker was happy to help in any way, so maybe that's where this comes from.

But "Informal" means there are no real rules.

That said, in very informal usage, between close friends or people from the same small grouping, then as noted above pretty much anything said after "thanks" counts as an acknowledgement.