Office Assist - Working with Office documents in Microsoft 365 (OneDrive, SharePoint and Teams)

Updated 12 May 2026 Storage & Integrations

The Foldr desktop apps for Windows and macOS provide a feature called Office Assist that allows locally installed Office apps to work natively with the online version of Office files hosted in Microsoft 365. The storage locations compatible with Office Assist are OneDrive, SharePoint and Teams.

Working online in this article means editing the cloud-hosted version of a document, which lets users benefit from native Microsoft 365 features such as AutoSave in Word, Excel and PowerPoint (in both the desktop and web apps), collaborative editing and more. When an online version is edited with a locally installed Office application, Foldr passes the online address of the document to Office and the save/upload process is handled entirely by the Office app and the Microsoft 365 cloud platform.

Office Assist on Windows lets users open documents online by double-clicking files in the Foldr drive, or by using File > Open inside Office. This uses a dedicated Office Add-in. Office Assist on macOS does not use an Office Add-in and provides a similar experience with slightly reduced functionality: users double-click files in the Foldr drive in Finder to open the online version, and opening the online version from inside the Office app (File > Open) is not possible on macOS.

Important update, August 2025: Foldr for Windows v4.5.6 includes Office Assist v2, which uses a new Foldr Office Add-in for the Word, Excel and PowerPoint apps to provide online working with Microsoft 365 hosted documents. Office Assist v2 in the v4.x Windows apps no longer relies on modifying file extensions on the Windows client. The feature is enabled automatically, but can be disabled per Office application (Word, Excel or PowerPoint) in the app settings > Office tab. Information and download links for upgrading from version 3.x to 4.x of the Windows app are available in the Windows app installation and configuration guide.

How to work online with Microsoft 365 documents: quick summary

A user can work online with Microsoft 365 hosted documents using ANY of the following methods in Foldr:

Ensure Office Assist is enabled in the Windows or macOS desktop apps. macOS users need to double-click the document in the Foldr drive in Finder to open the online version.
Use the Windows or macOS app’s context menu: right-click the document > Foldr > Edit in Microsoft Office.
Use the Foldr web app, which always opens the online version of a document.

Note 1: the locally installed Office app should be signed in with the same Microsoft 365 account as is linked in Foldr to edit online. This applies to editing from the Foldr web or desktop apps.

Note 2: the Foldr for Windows app must be running before an Office application (Word, Excel or PowerPoint) is launched for the Office Add-in to load successfully.

Desktop app editing mode (offline) on non-Microsoft 365 storage

Office files opened from any other storage type (SMB shares, Google Drive, S3 and so on) always open as a local / offline version that is downloaded to the local Foldr app cache. The difference between offline and online editing is significant and affects how the file is handled after editing. When working offline, the user clicks save in the Office app and the file is placed into the upload queue in the Foldr app, using the standard Office save mechanism (a temporary file is created, the existing document on the remote storage is deleted, and the temporary file is renamed; Office owner files are also created and deleted along the way). When working online, the user does not need to click save at all: changes are uploaded automatically and directly between the client machine and Microsoft’s cloud platform.

Without Office Assist enabled (or one of the other online methods above), the Foldr app opens Office documents in Microsoft 365 locations as a local offline version. Offline editing does not support collaborative editing, and traditional file locking is not possible, so it is not desirable to have users working this way on documents in shared Microsoft 365 storage areas such as SharePoint and Teams. Multiple users reaching the same document via different routes can end up editing at the same time, and depending on who saves last this can result in data loss. Opening documents online avoids these issues, so Office Assist is recommended and should be enabled where users work with Office documents in OneDrive, SharePoint or Teams.

Foldr provides other features to help mitigate these issues when working with documents on SMB (Windows file server or NAS) shares. See the Checkouts article to learn about Foldr’s checkouts and its complementary file locking service. Checkouts may be used on all storage types, not just SMB shares; the file locking service is an SMB-specific feature.

How to tell whether you’re working online or offline

A quick way to tell is the status of the AutoSave option in the Office application. When you open an Office document from the Foldr drive, AutoSave shows the relevant status automatically; the user does not need to change it.

Online = AutoSave on

Screenshot: How to tell whether you’re working online or offline

Offline = AutoSave off

Office Assist setup - Windows

Office Assist is enabled by default in Foldr for Windows v4.x and Foldr for macOS. It can be configured in the following places:

The user can enable or disable it in the Foldr app settings.
The Foldr administrator can enable or disable it centrally using an App Profile on the Foldr server. When the Office Assist state is controlled via an App Profile, the user cannot change it in their app settings.
It can be set at install time using an install argument for Windows and macOS, or by pushing out registry keys on Windows or app preferences on macOS. As with App Profiles, the user then cannot change the state in their app settings.

App Profiles are recommended where the administrator wishes to disable or enforce Office Assist en masse, as they are controlled centrally and require no changes on the client machine.

To check the state in the app, open the app settings from the Foldr system tray icon’s context menu and click the Office tab to confirm Office Assist is enabled for the Office apps as required.

Setup is then complete. Microsoft Office documents in the Foldr drive that are hosted on OneDrive, SharePoint sites or Teams channels will open online, with AutoSave enabled in the Office applications.

Office Assist setup - macOS (double-click to open online)

To enable Office Assist on macOS the user only needs to enable the option in the app settings; unlike Windows, no other steps are required.

Click the Foldr icon in the macOS menu bar and select Settings, click Advanced, then enable the option labelled Use Foldr to open Office 365 documents.

What happens when File > Open is used inside Office apps?

On Windows, a user can open the online version of a Microsoft 365 hosted document either by using File > Open inside an Office application or by double-clicking the file in the Foldr drive in Windows Explorer. On macOS it is not possible to open the online version from inside the Office app using File > Open, because macOS does not support VSTO Office Add-ins, which are a Windows-only feature.