JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
If I understand you correctly, you would like to preview the form in your browser. If yes, then just click the "Preview" button in the form builder.
In the Preview wizard, there's also an option to open the form in a new tab.
If you are referring to a function where you can preview the answers before your user can submit it, then please use the Preview Before Submit widget.
Hope that helps. Thank you.