Suppose you finished reviewing a large video saved in a synced OneDrive folder. You want to keep it online and reclaim its space on this Windows computer. Check that syncing has finished and that the right file opens in OneDrive on the web before changing its local availability.
Use Free up space in File Explorer
With Files On-Demand enabled, right-click the file in File Explorer and select Free up space. Its icon should change to a blue cloud. The file still appears in the folder, but opening it requires a connection and downloads it again. Using Delete instead would remove it from OneDrive, including your other synced devices.
Verify before going offline
Confirm the file is still present on the web. If you later need it without a connection, choose Always keep on this device, wait for the download and look for the filled green circle with a check mark. Open the file before leaving to verify you have the intended copy.