Is it possible to run the s3 sync command but only upload the files based on file size and not just include the modified date time of the file?

I am currently running:

aws s3 sync ./../app/dist s3://mywebsite.me/dist --acl public-read

The issue I have is I run gulp commands prior to this and files are generated even though the contents of the files are not changed.

Then doing the sync causes files to be uploaded that have not been modified in terms of content.