Can I use my VSTO & VBA excel addins with Office365?

Question

All the questions/answers I have seen so far are old and do not provide a definitive answer.

Also what can I use locally and what can I use online?

Answer 1

what can I use locally and what can I use online?

You may use your VSTO and VBA add-ins for Office Desktop application on Windows.

Office applications on Web (online) has extensibility via Office.js API. Microsoft current name is "Office Add-ins", you may try them by loading into your Office application (excel) from Office Store. If you want to develop add-in based on this technology I would suggest to start over here: Office Add-ins platform overview . The conception behind of this technology is "build once, use everywhere where Office runs". That means your add-in may work for Office Desktop on Windows, Office Desktop on Mac, Online versions as well as some mobile platforms (subject to availability )