My question is:Yesterday, I opened an website. Which was providing web hosting for free. And I signed up with my account. After that there was a button their which said "Let's create some magic". And I clicked on that. There was no actual magic in their. Now, I want to know whether I was sinful for that or not?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

You are wrong for what you did. It is known that magic is one of the greatest evils, and pressing the button on ‘doing magic’ is in the sense of approving of it and being satisfied by doing it. This is not permissible even if you were joking.

Joking about evil is not excused as determined by the scholars; Ibn Al-Qayyim said:

“Allah and His Messenger have not made joking as an excuse by which one is exempted from punishment; rather, the doer is deserving of punishment, for Allah has excused the one who is compelled to say the word of disbelief while his heart is assured by faith, but He did not excuse the one who is joking, as Allah Says (what means): {And if you ask them, they will surely say, "We were only conversing and playing." Say, "Is it Allah and His verses and His Messenger that you were mocking?" Make no excuse; you have disbelieved after your belief.} [Quran 9:65-66] Similarly, the person who does something by mistake or by forgetfulness, he is not held accountable.” [End of quote]

So, seek the Forgiveness of Allah and do not do this again.

Allah Knows best.