You can use a CSV file to upload changes to the Gradebook. You can upload information for existing assignments, or you can also use a CSV file to create new assignments in the Gradebook. New assignments will automatically be published in your course. If you do not know how to save a file in a CSV format, please check the documentation for the program you are using to create your Gradebook changes (e.g., Excel).
If you don't want to create a new CSV file, you can always download the CSV from Canvas, change it, and re-upload the same file and the changes you made will appear in Canvas once you re-upload the CSV file.
If you create a column for a new assignment, Canvas will ask how you want to import the assignment. New assignments upload with the following settings:
For new files, save the file as Grades-Course_Name.csv.
Required columns and order
In Course Navigation, click the Grades link.
Click the Actions menu  and then click the Import button .
Click the Choose File or Browse button (depending on your browser).
Locate the CSV file  then click the Open button .
Click the Upload Data button.
If you add a new column to the CSV file and then upload the file, Canvas will ask you what you want to do with the new column. In the drop-down menu, choose the A new assignment option . Then assign the number of points possible . Click the Continue button .
Review the changes made to your Gradebook .
If you upload assignments with no grade changes, they will be hidden from the upload.
Click the Save Changes button .
View the updated data in the Gradebook.