Photo by Robin Pierre

Article Updated: Feb 15, 2022

Synchronization… The thing that makes it possible for local files to end up in OneDrive on the web, and vice versa. Microsoft have had this feature for files in OneDrive and SharePoint for a while now, but now Microsoft List can be synced locally with the Lists app.

This article will introduce the List sync feature and it’s current limitations.

The App

When you visit the online Lists app in M365 you should see:

The app is a PWA and I’m not sure why you would need it to sync (as the list sync engine seems to be built into the OneDrive sync engine), but for me, the sync status didn’t show up until I installed the app.

Once local sync is working, you will see a checkmark icon beside your list name:

When it’s syncing a change, you should see the status icon change:

The Process

Lists sync runs from a process called Microsoft SharePoint and can be found in Task Manager:

The executable file can be found in the OneDrive folder structure:

Note: Lists sync came out of a project codenamed Project Nucleus. It was stated that “Nucleus will be powering the next generation of OneDrive and SharePoint web applications focusing on performance, local installation, seamless updates and basic offline capabilities. The focus is quickly rendering fully interactive content using modern Microsoft Edge and Chromium based browsers. “(Video posted to the M365 Community).

Testing

According to Microsoft documentation, you can only sync locally with a very specific set of conditions.

I decided to test these limitations and record my results.

Limitation	Results
List sync is currently supported only on Windows 10 devices.	Tested in Windows 10 and 11 and it seems to work in both. Not tested on other operating systems.
A full offline experience for lists—where you can perform all of the operations that are available online—is not yet supported. See item 3 below.	True. You can’t add/edit columns, create views, or generally modify the structure of the lists.   Edit in grid view (through the button bar but the item level button seems to work), sharing, automation, and version history are also disabled.
Currently, not all types of lists can be synced. The lists that are not supported right now are prevented from syncing, and no “sync icon” appears on the list. Following are the kinds of lists that aren’t synced:	See individual results below.
Lists that have the Allow management of content types set to Yes	Just turning it on doesn’t seem to stop the sync. Adding a 2nd content type disables offline sync (even if it’s not included on the New button).
Lists that have the “Allow items from this list to be downloaded to offline clients” set to “No”	True. This setting disables sync immediately.
Lists that have the Require content approval for submitted items set to Yes	True. This setting disables sync immediately.
Lists that have Make “New Folder” command available set to Yes	True. This setting disables sync immediately.
Lists that have display mode set to Classic experience	This didn’t seem to disable sync. The list appears in modern view in the app.
Lists with Calculated fields	True. This field type disables sync immediately. ☹
Lists with Lookup fields	True. This field type disables sync immediately.
Lists with validation formulas on any of fields	True. This setting disables sync immediately.
Lists that have Multiple lines of text fields where Append changes to existing text is set to Yes	True. This setting disables sync immediately.
Lists with fields that have default value specified.	I tested this with Default static text on Test and choice columns and it seemed fine. As soon as you choose a calculation for the default the list will not sync.
Besides the restrictions above in item 3, there is the limit regarding which lists can be synced to your device: Only eligible lists created by you, or lists that were shared with you and opened by you, will be synced to your device. This includes lists that are visible in the Lists web app (Favorites, My Lists, Recent Lists). And if you delete a list or lose access to a list, it will be automatically un-synced from your device.	This seems true.

I decided to test a couple of other criteria to see how sync worked:

Criteria	Results
Using the Term Store (Managed Metadata)	This field type disables sync immediately. Once I removed this column, I couldn’t get the sync working properly again.
Using a Location column	Note: I have issues with the Location column working in the Lists app (PWA version) at all.   Will sync with the column added, but the column will not work.
Using a Person column	Will sync with the Person Column, but the field is disabled for new items and item updates when offline.
Adding a Calendar View	Works as expected
Adding a Board View	This view disables sync immediately (I think this view is still in Targeted release).
Using Attachments	When offline, attachments are disabled for new items. Current items allow clicking of attachments, but it launches a browser and fails to open the URL.
Configure the List Form	I could not get the Header, Footer, or Body sections to hold form configurations with a synced list. The updates would be removed after refreshing the list. I tried configuring the forms in SharePoint, Lists (web), and Lists (app).
Using Rules	I only tested the add new item rule, but it seems to send the email when the item is synced.
Versioning	Item versioning seems to work offline. I made 3 separate updates to an item and after the sync the version history showed all 3 updates separately.
Using a Power App Customized Form	Adding the form did not disable the sync. The Power App version of the form did not display (as expected), but it did not fall back to the regular form which made new items and updates impossible.
Using a Power Automate Flow	Tested using the “When an item is created or modified” trigger, the flow fired when it was synced back from an offline state. I added a new item and made 3 separate updates to an existing item. The flow fired once for the new item, and once for the 3 updates to the other item. For the updated item, it was able to detect that it went through 3 version and detected all the updated fields correctly.

Conclusion

I would say it’s early days, but overall, I found the list sync experience constraining and somewhat inconsistent.

Note: I was doing a lot of structural changes to lists, so it’s possible that was the reason for the weirdness I witnessed.

Sometimes the list would sync quickly and other times the refresh icon would appear for several minutes for a simple value change. There is also no “log” like in OneDrive so you can see what is happening. That’s probably more difficult here because we are not talking about items that appear on your hard drive, but minimally, a local sync indicator would be helpful.

As someone with a lot of experience with SharePoint lists, it seemed like much of the power behind lists is removed when the limitations come into play.

I’m really hoping to see some of the limitations and issues addressed. Project Nucleus is supposed to address the 5000-item view limit, which has plagued SharePoint lists for far too long. I understand limitations like not being able to look up users when offline, or even disabling for lookups, but I do feel like the current trade-offs are too much to make the offline sync useful. That said, I can see the potential in this feature, so I’ll be keeping an eye on it.