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.
This would mostly depend on the features that you would like to compare, but in general with JotForm, you will have more payment options available to be added to your forms and you have a larger number of widgets that you can add to your forms.
This means that you will be able to customize your forms to better fit our requirements.
Making a quick look they offer 40 integrations, while on JotForm you have access to 107 integrations
Now I can not quickly find the widgets that they might have (fields), but with JotForm, next to the standard fields / tools for your form, you have access to 374 additional widgets.
Now I do recommend to try to recreate the form you have on FormStack to see how easy it is to create a form and how good it works and if you have any additional questions, please do let us know.