Sideload Office Add-ins in Office Online for testing

You can install an Office Add-in for testing without having to first put it in an add-in catalog by using sideloading. Sideloading can be done on either Office 365 or Office Online. The procedure is slightly different for the two platforms.

When you sideload an add-in, the add-in manifest is stored in the browser's local storage, so if you clear the browser's cache, or switch to a different browser, you have to sideload the add-in again.

Note: Sideloading as described in this article is supported on Word, Excel, and PowerPoint. To sideload an Outlook add-in, see Sideload Outlook add-ins for testing.

The following video walks you through the process of sideloading your add-in on Office desktop or Office Online.

Sideload an Office Add-in on Office 365

  1. Log on to your Office 365 account.

  2. Open the App Launcher on the left end of the toolbar and select Excel, Word, or PowerPoint, and then create a new document.

  3. Open the Insert tab on the ribbon and, in the Add-ins section, choose Office Add-ins.

  4. On the Office Add-ins dialog, select the MY ORGANIZATION tab, and then Upload My Add-in.

    A dialog titled Office Add-in with a link near the upper left corner that says "Upload My Add-in".

  5. Browse to the add-in manifest file, and then select Upload.

    The upload add-in dialog with buttons for browse, upload, and cancel.

  6. Verify that your add-in is installed. For example, if it is an add-in command, it should appear on either the ribbon or the context menu. If it is a task pane add-in the pane should appear.

Sideload an Office Add-in on Office Online

  1. Open Microsoft Office Online.

  2. In Get started with the online apps now, choose Excel, Word, or PowerPoint; and then open a new document.

  3. Open the Insert tab on the ribbon and, in the Add-ins section, choose Office Add-ins.

  4. On the Office Add-ins dialog, select the MY ADD-INS tab, choose Manage My Add-ins, and then Upload My Add-in.

    The Office Add-ins dialog with a drop down in the upper right reading "Manage my add-ins" and a drop down below it with the option "Upload My Add-in"

  5. Browse to the add-in manifest file, and then select Upload.

    The upload add-in dialog with buttons for browse, upload, and cancel.

  6. Verify that your add-in is installed. For example, if it is an add-in command, it should appear on either the ribbon or the context menu. If it is a task pane add-in, the pane should appear.