What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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.
Unfortunately no, it is currently not possible to apply a custom css to many forms. Same for adding the same field to all forms.
We are actually working on a new tool that will make it possible to create your own custom themes for jotform. Just like custom CSS. So, once we have that you will be able to use the same theme on many forms and that way apply the same custom CSSes to all of the forms.