What format do you use when uploading the bulk of learners to assign a course?

Hi All,

I wanted to get your thoughts and learn from your experience.

When you need to assign a course to a large number of learners at once, what file format do you typically use to upload the learner list?

Do you use CSV, Excel, Notepad/text file, or another format?

If you have a preferred format, it would be great to hear why you use it and whether you have found it easier or more reliable for bulk learner assignments.

Looking forward to hearing what everyone uses!