My prescription is 1mg of alprazolam, but i only take half, at night...is it okay if i take 1/4 of it a little before and the other 1/4 later at night?

Let MD know, but yes: If this allows you to rest comfortably at night the less medication the better, although if you find yourself always having to wake up then taking a half tablet up front rather than a fourth may work better for you. I would let your doctor know as soon as possible that you are not needing as much medication so that they can reduce your prescription in accordance with the change in the evening.