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.
We use a standard input with a type 'file' for a Single Upload field. That standard field is being handled by the native upload field implementation of the internet browser, and we have no control over it. It means that the progress bar is a part of the Google Chrome browser, but unfortunately, there is no such progress bar implemented by the Safari browser.
Please feel free to contact us if you need any further assistance.