Translation:It's up to you!
I agree. There are any number of possible English translations or conversational equivalents for 随便你 besides 'It's up to you.' The idea conveyed is that you are being given the choice. Some additional equivalents: (do) as you like, (do) as you wish, (do) as you please, it's your choice, the choice is yours, it's your decision, it's your call, whatever you like, whatever you want, suit yourself. I'm not in favor of accepting 'have it your way' or 'please yourself' which though they tell someone to make his or her own choice, seem to express personal displeasure with that choice.
Besides it's use in other polite or friendly expressions, such as 随便吃吧, help yourself (=eat what you like), 随便 can also be used to mean willful, arbitrary, or deciding one sidedly, without properly considering others: 说话随便, not be careful about the way one talks. The Chinese examples are from the top notch Pleco dictionary app.
I think 'suit yourself' is close in English to the Chinese too. The Chinese literally says 'follow your own self" so 'as one pleases' or 'as you wish' are all possible and acceptable answers.
When you hover over 随便, it shows 'just'. If we have not seen these words before, how are we suppose to know they mean 'as one wishes'. Please correct the clue.
Time-wasting methodology. I take these classes as a hobby, not to get frustated with these mistakes.
The translation is "just", but "It's just you" is WRONG. How strange!
'Whatever you want' is accepted and 'whatever you like' is not? Please update that.
When you say "up to you" verbally, the "It is" at the start is implied. You should include it when writing. Similarly when you say "got it". The "I have" at the start is implied when spoken, but you should write it.
隨便你 is informal and is only used verbally. Therefore the "it is" at the start is not necessary.
"As you wish" is not an exact synonym for "it's up to you". Tarkin: "Lord Vader, how should we torture the prisoners?". Vader: "It's up to you." Tarkin: "Let's water board them then!" Vader: "As you wish."
Whether it's also a valid translation is a different question, about which I have no idea :-)
As a native speaker, I think "随便你！" can imply "I don't want to care!" in some cases, so you have to be careful if you want to use this phrase. Other natives agree with me?
Note that the traditional form 隨 and simplified form 随 are different.
ATTENTION! -—> wrong audio for these characters: 随便你!
The audio says 随给你 = suí gěi nǐ = With you!
-—>But the Characters written in the test are spelled 随便你!
随便你! means ==>Suíbiàn nǐ! = Up to you!