Debug add-ins in Office Online
You can build and debug add-ins on a computer that isn't running Windows or the Office 2013 or Office 2016 desktop client - for example, if you're developing on a Mac. This article describes how to use Office Online to test and debug your add-ins.
To get started:
Get an Office 365 developer account, if you don't already have one, or have access to a SharePoint site.
To sign up for a free Office 365 developer account, join our Office 365 developer program.
Set up an add-in catalog on Office 365 (SharePoint Online). An add-in catalog is a dedicated site collection in SharePoint Online that hosts document libraries for Office Add-ins. If you have your own SharePoint site, you can set up an add-in catalog document library. For information, see Publish task pane and content add-ins to an add-in catalog on SharePoint.
Debug your add-in from Excel Online or Word Online
To debug your add-in by using Office Online:
Deploy your add-in to a server that supports SSL.
We recommend that you use the Yeoman generator to create and host your add-in.
In your add-in manifest file, update the SourceLocation element value to include an absolute, rather than a relative, URI. For example:
<SourceLocation DefaultValue="https://localhost:44300/App/Home/Home.html" />
Upload the manifest to the Office Add-ins library in the add-in catalog on SharePoint.
Launch Excel Online or Word Online from the app launcher in Office 365, and open a new document.
On the Insert tab, choose My Add-ins or Office Add-ins to insert your add-in and test it in the app.
Use your favorite browser tool debugger to debug your add-in.
The following are some issues that you might encounter as you debug:
The browser might show an invalid certificate error that you will need to bypass.
If you set breakpoints in your code, Office Online might throw an error indicating that it is unable to save.