How to use Dropbox, OneDrive, Google Drive or iCloud as your main storage

With firms such as Google, Microsoft, Apple and Dropbox offering gigabytes or even terabytes of online storage, sticking everything in the cloud is an appealing idea - especially if you use lots of devices or need to access PC stuff on your mobile on tablet.

While you can't really use cloud services as your main storage on your primary PC or Mac - they merely copy what you're saving to your local hard disk or portable SSD - you can use their folder(s) as your default storage for documents, photos and other kinds of files - and you can then access some or all of those files from other computers, mobiles and tablets by opening individual files or syncing specific folders. But is it wise to put your important data in the cloud? Here are ten things to think about.

• Best cloud storage of 2019 online: free, paid and business options
• We also compiled the list of best online photo storage services
• It is advisable that you keep a local copy of your files, so check out our best NAS

Choose the right cloud

Different services have different requirements, so while Dropbox, Google Drive and OneDrive work on pretty much anything, iCloud needs a Mac running at least Yosemite and/or iOS devices running at least iOS 8 – and while there is an iCloud client for Windows, there isn't one for Android or other mobile platforms. It's important to think about the device(s) you might want to share with and check that there are apps available for those devices.

Don't put your faith in free

It's nice to get things for free, but free comes with no guarantees – terms and conditions, features and options can and sometimes do change with little or no notice, capacity tends to be fairly limited and there's no such thing as guaranteed availability without a price tag attached.

That doesn't necessarily mean you have to rush out and spend money, though, because many paid-for services are offered in packages with other purchases. For example, Office 365 subscribers get stacks of cloud storage (a whole terabyte) as part of their bundle.

Protect your phone

If you'll be sharing or syncing with your mobile device(s), protect them with PINs or passwords; there's no point observing strict security on your computer and then leaving your phone or tablet open for anybody to access your stuff.

UK's National Mobile Phone Crime Unit says that more than 300,000 phones are lost every year, but that's only the ones reported to claim against insurance – the real figure is much higher. If someone got your phone, could they access your stuff? Making sure they can't takes no time at all.

Know what's safe to store

The only absolutely, positively, definitely guaranteed way to ensure something can't be got from the internet is to make sure it never goes anywhere near the internet. While the risk of data loss or theft from well-known cloud services may be remote, it's still possible and something you need to think about – especially if you're storing work files with people's personal data, as the Data Protection Act says that data must be adequately protected. Don't want your world domination plans to fall into enemy hands? Use file encryption on anything you're putting in the cloud.

Turn on 2FA

A simple username/password combination isn't enough to keep your cloud storage secure, which is why the major cloud storage providers offer two-factor authentication, or 2FA for short. 2FA uses a second form of verification to make sure you're actually you, most commonly by sending a code to another device such as your smartphone or tablet. 2FA is also available for online services such as email and photo storage, and it's a very good idea to enable it on those too.

Always have a backup

While many services do their utmost to protect your data, there's always the risk that something can go wrong – and the more important the file, the more important it is that you have a backup copy of it. That might mean uploading photos to two different cloud services (something that's automatic if you install, say, Flickr on an iCloud-sharing iOS device and turn on the Flickr auto-upload so that both Flickr and iCloud get every image), or just regularly syncing and backing up key files.

Check what's connecting

Services such as Dropbox and Google Drive enable you to see just what devices have been connecting to your account, so for example Dropbox lets you see what web browsers are currently linked in and what particular PCs, Macs and mobiles you've given access to your account.

If there's a device that isn't yours or that you don't have any more, you can unlink the device to revoke its access. The device list won't include people you've sent shareable links to, such as Dropbox public URLs; it only covers devices with access to your account.

Revoke app access

Cloud storage doesn't just connect to devices directly – it can be called from within third-party apps too, so for example you might want Google Drive attachments in your email software, OneDrive files in your Office documents or to connect Dropbox to IFTTT.

Once again, your account dashboard enables you to see what apps have access, and to revoke the access of anything you don't need. The fewer apps that have access to your account, the more secure that account is likely to remain.

Don't exceed your allowance

One of the most common uses of cloud-based software is to provide access across devices, so for example you might want iCloud documents from your Mac available on your iPad, or OneDrive files from your PC on your, errr, Windows Phone.

That's great, but be careful if you're on a mobile data plan with a monthly traffic limit – too much file sharing and syncing can easily burst through your bandwidth limit, slowing your connection or incurring extra charges. If your account is capped, limit what you share or only sync when your mobile's got Wi-Fi.

Keep your payment details current

If you have a paid cloud account and the renewal doesn't go through you don't need to panic – Dropbox's approach is fairly typical, with accounts downgraded to free Basic accounts but the files remain untouched.

What does change, though, is the ability to sync – if your paid account has been knocked down to a basic, free account, that could mean storage space dropping from 1TB to just 2GB. If your files exceed that, you won't be able to sync anything new until you've re-subscribed to the paid account.