Questions regarding uploading files to forms

Is there a way to preview a file that was selected? (As a way to ensure the user uploaded the correct file)

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. 

https://www.jotform.com/help/29-Which-file-types-are-allowed-for-the-upload-field

If you need any further help by our side for this issue or any other, please do not hesitate to contact us.