Your files are in the cloud — but also on your disk. Here's how to fix that

Q: How much space can Files On-Demand save?

It depends on your OneDrive size. If you have 50 GB synced locally and make most of it online-only, you could reclaim nearly all of that. Work accounts with shared folders can save even more.

Q: Why are files re-downloading after I freed them?

Some apps and macOS features like Spotlight indexing may open files, triggering OneDrive to download them. You can exclude OneDrive from Spotlight in System Settings to prevent this.

Updated September 2026 · 7 min read

OneDrive is Microsoft's cloud storage, and if your workplace uses Microsoft 365, it's probably running on your Mac right now. The problem many people discover: OneDrive has been quietly downloading their entire cloud library to the local disk. On a work account with years of shared documents, presentations, and spreadsheets, that can mean 20, 50, even 100+ GB of local storage used — for files you may have never opened on this computer.

The solution is Files On-Demand, a OneDrive feature that keeps your files in the cloud until you actually need them. Here's how to set it up and reclaim that space.

How OneDrive uses your Mac's storage

OneDrive on Mac creates a folder (usually ~/OneDrive or ~/OneDrive - YourCompany) and syncs files between the cloud and your local disk. By default, it may download everything — or it may already use Files On-Demand, depending on how your IT department configured it.

Here's how to tell what's happening:

Cloud icon (outline only) next to a file: the file is online-only. It's visible in Finder but doesn't use disk space.
Green checkmark: the file is available locally and in the cloud. It uses disk space.
Blue sync arrows: the file is currently syncing.

If most of your files show green checkmarks, they're all stored locally — and that's where your disk space is going.

Enable Files On-Demand

Click the OneDrive icon in your Mac's menu bar (the cloud icon).
Click the gear icon, then Preferences (or Settings).
Go to the Sync and backup (or Account) tab.
Look for Files On-Demand and make sure it's turned on.

With Files On-Demand enabled, OneDrive shows all your cloud files in Finder, but only downloads them when you open them. Files you haven't opened stay as lightweight placeholders — they look normal, are fully searchable, but use almost no disk space.

Free space from already-downloaded files

Enabling Files On-Demand prevents new files from downloading automatically, but files that are already on your disk stay there. To reclaim that space:

Open your OneDrive folder in Finder.
Right-click a file or folder you don't need locally.
Choose Free Up Space.

The local copy is removed and the file reverts to an online-only placeholder. It's still in your OneDrive, still visible in Finder, and downloads instantly when you open it.

To do this in bulk, right-click your top-level OneDrive folder (or large subfolders like "Documents" or "Shared") and choose Free Up Space. OneDrive converts everything inside to online-only in one step.

When not to do this: if you work offline regularly — on planes, in areas with unreliable Wi-Fi — keep the files you use daily set to "Always Keep on This Device." Making everything online-only means you can't open those files without an internet connection.

Pin files you need offline

For files you always want available on your Mac, regardless of internet access:

Right-click the file or folder in Finder.
Choose Always Keep on This Device.

These files get a solid green checkmark and stay downloaded permanently. Everything else can safely be online-only.

OneDrive cache: the other storage consumer

Beyond your synced files, OneDrive also keeps application cache and metadata:

~/Library/Caches/com.microsoft.OneDrive — temporary data, usually a few hundred megabytes.
~/Library/Application Support/OneDrive — sync databases and logs.

These are typically small compared to the synced files themselves, but if you've been using OneDrive for years, clearing the cache folder can free 200–500 MB. Quit OneDrive first, delete the cache contents, and reopen — OneDrive will rebuild what it needs.

For a broader look at cloud storage and other apps consuming your disk, see our Dropbox guide — the same online-only concept applies there too.

See exactly where your storage goes

Gigatidy scans your Mac and shows what's using space — OneDrive sync, app caches, system data, and everything else — then helps you clean what's safe.

Meet Gigatidy →

FAQ

Does "Free Up Space" delete my files from OneDrive?

No. It only removes the local copy from your Mac. The file stays safe in OneDrive's cloud and remains visible in Finder as an online-only placeholder. You can open it anytime — OneDrive downloads it on demand.

How much space can Files On-Demand save?

It depends on how much is in your OneDrive. If you have 50 GB synced locally and make most of it online-only, you could reclaim nearly all of that. For work accounts with shared folders, the savings can be even larger.

Why are files re-downloading after I freed them?

Some apps and macOS features (like Spotlight indexing or preview generation) may open files, which triggers OneDrive to download them. If files keep re-downloading, check if an app is accessing them. You can also exclude your OneDrive folder from Spotlight in System Settings → Spotlight → Privacy.