To begin, all current Challenger products (online and offline) utilize Internet browser applications (IE, Firefox, Chrome, Safari, etc) to read and present data.
This answer to "online versus offline" revolves around "where is your content and score data coming from and going to." If it's www.challengercme.com via an active Internet connection, then you're working online. If it's your local hard drive or local storage, you're offline (even though you're using a web browser.)
Another way to state it is...
If you go to www.challengercme.com and log into the Challenger Learning Portal, you are working online. An internet connection is required.
If you've downloaded the Challenger Offline Viewer to your laptop or desktop computer and working with courses downloaded to your Offline Viewer, you are working offline. No Internet connection is required to use your Challenger courses. However, you will want to Sync Scores, with an internet connection, to send your scores back to our online learning portal. That's how you'll earn CME.
If you have additional questions or experience any difficulties, please submit our support form or contact us by phone at 1-888-242-5536. We offer free, live, US-based support Mon – Fri, 8am – 5pm CT.