Upload limit is determined by your hosting provider. You can however try overwriting these values, check out this article: http://www.wpbeginner.com/wp-tutorials/how-to-increase-the-maximum-file-upload-size-in-wordpress/
I seriously doubt that you will be able to upload 1GB files however, I’d imagine the script would timeout. Larger files should be uploaded via FTP and added to Delightful Downloads once completed, which will be possible in the next update.
thank you! I am looking forward to the next update! do you have a release date?
THANK YOU VERY MUCH!
The next update is currently being tested, so not long until release.
Ashley
