Over time, cloud storage services have evolved: It used to be that everywhere you installed Dropbox, or Google Drive, or whatever your client of choice was, you'd get all of your files synced to that computer, ready to access instantly.

Now, the default behavior tends to be that files are kept online in their entirety, with placeholders stored on your local Windows or macOS system. The idea is that you use up much less space on your machine, and you can still get your files whenever you need them—they just take a couple of seconds to open as they're downloaded from the cloud.

This newer approach has its advantages, but it's not always ideal, especially if you're going to be without a reliable internet connection for an extended period or you're constantly making changes to a particular file, for example.

Here are the ways you can make sure your most important files are stored locally, using any of the popular cloud storage services. It'll definitely take more local disk space, but your data is easier to access, whether you're online or not.

OneDrive comes built into Windows. Access it via the Start menu or through the left-hand navigation pane in File Explorer. Once you get to the folder, you'll see little icons next to your files and folders: A blue cloud icon indicates it’s available only online, a green tick indicates available locally, and a solid green tick means a file or folder is always available locally (so OneDrive won't ever remove the local copy).

The easiest way to make sure that a file or folder is always saved to disk in Windows is to right-click on it and check the Always keep on this device option. You'll see the icon change to a syncing one (two arrows) before the solid green tick appears. If you change your mind and want to make a file or folder online-only again, uncheck the Always keep on this device option.

If you're using OneDrive on macOS, you can get at it through the Applications folder in Finder or from the menu bar, if it's currently running. To change the status of a file or folder, right-click on it and select Always Keep on This Device—the gray cloud icon will change to a gray tick icon. To go back to having a file or folder online-only until it's needed, right-click on it and select Free Up Space.

iCloud comes built into macOS, and you can get to your iCloud Drive folder from the left-hand navigation bar in Finder or by searching for it in Spotlight. Files that are online-only will have a gray cloud and arrow icon next to them, while files that are saved to the local drive will have no icon next to them—they'll appear just like any other file on disk.

To change the status of a file or a folder in your iCloud Drive, right-click on it and choose Download Now (you'll notice that the gray icon disappears once all of the downloading is complete). To reverse the process, right-click on a file or folder and pick Remove Download from the pop-up menu.

iCloud is available for Windows as well, and if you have it installed, you'll see it appear in the left-hand navigation pane in File Explorer. The syncing system is the same as it is for OneDrive for Windows: Right-click on a file or folder and check or uncheck the Always keep on this device option to control access to it.

On Windows, you can get to your Dropbox folder from the Start menu, the left-hand pane of File Explorer, or the system tray (to the right of the Taskbar). Icons next to files and folders indicate their status: A gray cloud for online-only, a green tick for available offline, and a solid green tick for permanently available offline, until you change your mind.

To set an item to be permanently available from the local disk in Windows, right-click on it and choose Dropbox, then Make available offline. The blue syncing icon appears (two arrows), then you'll see the solid green tick. Right-click on a file or folder and choose Dropbox and then Make online-only to reverse the process.

Dropbox on a Mac can be found on the menu bar if it's currently running and in the left-hand navigation pane in Finder (either through Dropbox or Applications). The icons are the same as on Windows: To download a file or folder, you need to right-click on it and pick Make available offline. To reverse the process, right-click on it and pick Make online-only.

If you have the Google Drive desktop client for Windows installed, syncing files from your cloud storage locker to the local hard drive, you'll see a new virtual drive appear in the This PC section of File Explorer. Go into My Drive, and all your files and folders will be visible—they just won't be stored locally on your hard drive.

To change this, right-click on a file or folder and pick Show more options, Offline access, and Available offline. As you might expect, to return the file or folder to its default state, you need to right-click on the item again and this time choose Show more options, Offline access, and Online only.

On macOS, the Google Drive folder appears in the left-hand navigation pane in Finder. The shortcuts you need to know are similar to the ones on Windows: Right-click on a file or folder and pick Available offline to make sure a local copy is always available, and right-click on a file or folder and pick Online only to go back to the default state.