To simplify things, we looked through over 100 of the highest-rated apps for each product (Outlook, Word, Excel, and PowerPoint), installed and tested 47 add-ins that stood out for their different features, and narrowed the results down using the following criteria:įree: There are a lot of promising paid apps available for Office products, but we wanted to focus on the best free add-ins. There are over 2,000 add-ins for Microsoft Office 365-and more that only work on specific versions of Office for Windows and Mac. How We Selected the Featured Microsoft Office Add-ins New to Office Online? Check our in-depth guides to Excel Online and PowerPoint Online to get the most out of Microsoft's free Office web apps.