SharePoint Sync button missing: how to find the cause

Short answer: check four things in order. First, ask whether the library or site has Offline Client Availability set to No. Second, check the view style if you use the classic experience. Third, check that you are signed in to the right account. Fourth, ask your admin whether the Sync button was hidden for the whole organization. This guide is about document libraries.

What the missing button means

The Sync button in a document library connects the library to the OneDrive sync app, so the files show up in File Explorer on Windows or Finder on a Mac. When the button is not on the toolbar, the browser page is hiding it. The files are still there.

Microsoft's troubleshooting page for OneDrive sync describes this case. It says: "A SharePoint administrator may prohibit syncing for a SharePoint site or library. In this case, you will see the following symptoms:" and the first one is: "When you view the library in a browser, the Sync button is missing." The page also lists an error you may see when you try to sync: "Options set for this library by your administrator prohibit users from syncing it to a local computer. For more information, see your SharePoint administrator."

That is one cause. It is not the only one. The sections below go through each cause that Microsoft's pages describe.

Before you start

Open the library in a browser, not in File Explorer. The button lives on the library page, for example in a site you open from https://www.microsoft365.com.
Note who can see the button. If a teammate sees it and you do not, the cause is likely tied to you: your permissions, your sign-in or your view. If nobody sees it, the cause is likely on the library or the site.
Exact names of buttons and settings may differ in your version of SharePoint.

Step 1. Check Offline Client Availability on the library

Microsoft's troubleshooting page covers this setting for the library and for the site. You need to be an administrator of the library to change it. Microsoft gives these steps for a library administrator:

Browse to the library.
Choose the Library tab, then choose Library Settings. Microsoft adds: "If you don't have the Library tab, select the Gear icon for the Settings menu and then select Library settings."
In the General Settings section, choose Advanced Settings.
In the Offline Client Availability section, choose Yes.
Choose OK.

If you cannot open Library settings, you are not a library administrator. Skip to Step 5 and ask the person who is.

Step 2. Check Offline Client Availability on the site

The same setting also exists for the whole site. Microsoft gives these steps for a site administrator:

Browse to the SharePoint site.
Choose the Settings gear, then choose Site Settings.
In the Search section, choose Search and Offline Availability.
In the Offline Client Availability section, choose Yes.
Choose OK.

A Microsoft Q&A answer to a person with the same problem says the admin "may disable SharePoint sync at the library level or at the site level." A later reply in that thread says the site-level option was No, was changed to Yes, and "The sync button appeared". That is one person's report, not a promise that it will work for you.

Step 3. Check the view style (classic experience only)

If you use the classic experience, a view can hide the toolbar buttons. Microsoft has a page about this. It says that in the classic experience these controls are missing: New, Upload, Sync, Edit, Manage and Share. Its fix is: "use the Default style within the view for the affected library. Or, switch to Modern Experience."

Microsoft explains the cause this way: "This problem occurs when you use a view for the document library if the view style is configured to any setting other than Default."

The Q&A thread above also mentions that switching to the classic view did not bring the button back in that case. So this step matters only if your library is shown in the classic experience.

Step 4. Check that you are signed in

Microsoft's troubleshooting page says: "If you aren't signed in to the SharePoint Online site, you should log in and select the Keep me signed in option to make sure the OneDrive for work or school synchronization process works well." It also says to use the credentials tied to the library, and adds: "In most cases, this will be your Microsoft 365 credentials."

Sign out of the site, sign in again with your work account, and look at the library page again. If you have two accounts in the same browser, one personal and one for work, try a private browser window with only the work account.

Step 5. Ask your admin about a tenant-wide setting

An administrator can hide the Sync button for every SharePoint library in the organization. Microsoft's page "Sync in SharePoint and OneDrive" says: "You can turn off OneDrive sync from all the SharePoint libraries in your organization with SharePoint Online Management Shell." The setting it names is HideSyncButtonOnTeamSite. The page adds: "Removing the sync button blocks new syncs from being started but doesn't affect existing syncs."

If your company turned this off on purpose, you will not get the button back. Your admin can tell you why.

Another way to get the files: a OneDrive shortcut

The same Microsoft page says users have two options: they can add shortcuts to libraries and folders in their OneDrive, or use the Sync button in the library. It also says: "We recommend using OneDrive shortcuts as the more versatile option." Microsoft explains that shortcuts let you reach content on all devices, while sync is tied to one device. If the Sync button is gone and your admin has not blocked shortcuts, a shortcut may give you the files in your OneDrive. Our advice, not a Microsoft rule: ask your admin before you rely on a shortcut.

What to tell your admin

A short message gets a faster answer than "sync is broken." Send these four facts:

The full web address of the library.
Whether a teammate can see the Sync button.
Whether you see the message "Options set for this library by your administrator prohibit users from syncing it to a local computer."
Whether the library uses the classic or the modern experience.

What to avoid

Do not rename a synced folder on your computer. Microsoft's page warns: "Do not rename the synced folder after the sync is established. That will break the sync relationship."
Do not reinstall Office or OneDrive as the first step. Our advice, not a Microsoft rule: if the button is missing in the browser, check the library and site settings first, because the button lives on the web page.
Do not change library or site settings if you do not own the site. Our advice, not a Microsoft rule: write down the old value before you change anything, so you can put it back.
Do not use sync as a backup. A synced folder mirrors changes, including deletions. Microsoft's page says: "If the user adds, changes, or deletes files and folders on the site, the changes also apply to the files and folders of the user's computer and vice versa."

Our advice for teams that use SharePoint for tracking

If your team tracks work in SharePoint lists, you may not need to sync files at all. A list lives in the browser and opens on any device. One way to start: keep documents in a library with a link column in the list, and keep the working data in the list. For list permissions, see "Fix "Access denied" on a SharePoint list".

When to get help

You can build all of this yourself in Microsoft 365. If you would rather have it built and tested for your team, I do that. A tracker like this is a fixed price: $5,000 for one, built in 2 weeks. See "What a SharePoint tracker costs to build". Bring one example of the problem to a free call.

Tell me what's still manual

I am Al Davies. I run 250 High Street LLC and build SharePoint trackers and Power Automate flows for operations teams. I work remotely. The first call is free, and I will not try to sell you anything.

See trackers I built: Tools I built

FAQ

Why can my coworker see the Sync button and I cannot?

The button depends on the library, the site and your view of the page. Compare four things between you and your coworker: your sign-in account, the experience you use (classic or modern), the view you have open, and whether you can open Library settings. A difference in any of them points to the next step to check.

Where is the Offline Client Availability setting?

It is in two places. For a library, it is under Library settings, then Advanced Settings. For a site, it is under Site Settings, then Search and Offline Availability. Microsoft's troubleshooting page lists both. Exact names may differ in your version.

I changed the setting to Yes and the button is still missing. What now?

Reload the page after you sign out and sign in again, then check the view style and the tenant-wide setting. If both look fine, ask your admin.

Does the Sync button work on a SharePoint list?

The pages in this guide are about document libraries. A list holds rows of data, not files in folders. Our advice, not a Microsoft rule: look for the Sync button on a document library, not on a list.

Will my files be lost if the Sync button is hidden?

No. The files stay in the library on the site. Microsoft says that removing the sync button "blocks new syncs from being started but doesn't affect existing syncs." You can still open, upload and edit files in the browser.