Which is more suitable Separate Box vs Single box in BrijPad

Question

I have created an editor for fast development BrijPad. I get feedback that there should be two boxes one for input and another for output. but I think for multiple operations it would be inconvenient.In this case user has to copy output to input again and again so i combined both boxes to one. Please let me know what the best solution is single box or double box for input and output.
Edit: One Box means same for input and output. suppose you type content in box and click on add prefix then you will get result in same box where you have typed similar to MS Word.

Double Box means One for input and another for output so you can compare both what you typed and what the result is.
Hope, It makes sense.

Answer 1

Assumptions: "input" is code, and "output" is how the code renders.

I'm looking around and I don't see any options for showing the code's output, just entering the "input" which I'm assuming is the code itself.

I would add a toggle between the edit mode and the preview mode, as well as an option for seeing both, in a screen split horizontally.

Answer 2

Cool app. Perhaps an option to toggle between one box vs two boxes would be the best approach? By default it could have separate boxes, but for more advanced cases the user could enable "multiple operations mode." How advanced are your average users?