If you set a file upload assignment to allow multiple attempts:
- Canvas does not overwrite the files from previous attempts.
- In SpeedGrader, you can select (and download) the files from the earlier attempt(s), as shown in this screenshot.
Latest attempt file upload (by default, Canvas will display the latest attempt):
Previous attempt file upload (note the warning that you are not viewing the latest attempt):
- However, if you bulk download the students' uploaded files, only the files from the latest attempt of each student will be downloaded.