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 you want to be sure file extension type, it is possible to adjust what you would like to allow your users to upload.
You may need to have a look following user guide. It explains how to configure it step by step.
If you need any further help by our side for this issue or any other, please do not hesitate to contact us.