Using the Tus upload approach, developers building client-side applications or integrating uploads onto their websites or services can use the metadata returned by the API to generate upload progress bars.
To generate an upload progress bar with the tus upload approach, you’ll need to make periodic HEAD requests to the upload_link
Read how at 'Working with Video Uploads' on our Vimeo Developer Page.
Comparing the Upload Offset (the amount of data on our upload servers) to the Upload Length (the size of the file you specified) will provide the necessary information to build a progress bar.