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.
Respondents of your form will be able to upload files to your form with the help of the "File Upload" field. You can find the File Upload field under Basic Fields of the form builder page.
With regards to the limit of file size that can be uploaded, I suggest you refer to this guide: https://www.jotform.com/help/33-Changing-the-upload-size-limit
To change the allowed file types/extension in the upload field, you may check this guide: https://www.jotform.com/help/29-How-to-Change-the-Allowed-File-Types-Extensions-in-the-Upload-Field
You may also find the guide below helpful in creating Upload Forms.
Please feel free to let us know if you have further questions regarding this and we will be glad to help you.
Thanks for your help