Once you've decided to actually back up your data properly, the next question is where it should live, and the honest answer is that no single option is best on its own. This guide compares the three main approaches — network-attached storage (NAS), external drives, and cloud backup — on the factors that actually matter, so you can combine them sensibly rather than picking just one.
The Three Options at a Glance
- External hard drive: A physical drive you plug directly into a PC via USB, storing a manual or scheduled copy of your files.
- NAS (Network-Attached Storage): A small dedicated device with its own drives, connected to your home network, accessible from any device on that network (and optionally from anywhere via remote access).
- Cloud backup: A service (OneDrive, Google Drive, Backblaze, iDrive, and similar) that stores your files on servers managed by a third-party company, accessed over the internet.
Cost Comparison
External drives have the lowest upfront cost and no ongoing fees — buy the drive once, and it's yours indefinitely. A decent 2–4TB external drive typically costs a modest one-off amount with no subscription attached.
NAS devices require a larger upfront investment: the NAS unit itself plus the hard drives to fill it (most NAS enclosures are sold empty). A basic two-bay NAS with drives can cost several times more than an equivalent-capacity external drive, but there are no ongoing subscription fees, and the device does much more than pure backup (media streaming, remote file access, running apps).
Cloud backup typically runs on a monthly or annual subscription. Costs vary enormously depending on the provider and how much data you store — some services charge per gigabyte, others offer unlimited backup for a flat annual fee per computer. Over several years, cloud subscriptions can end up costing considerably more than a one-off drive purchase, though you avoid any upfront hardware cost.
Speed Comparison
- External drives are fastest for both backup and restore, since data transfers directly over USB with no network or internet bottleneck. A full restore of hundreds of gigabytes can take well under an hour.
- NAS speed depends on your home network. Over a decent wired Gigabit Ethernet connection, NAS performance approaches that of an external drive; over Wi-Fi, especially older or congested Wi-Fi, it can be noticeably slower.
- Cloud backup is bottlenecked by your internet upload speed for backing up, and download speed for restoring. Most UK home broadband connections have far slower upload speeds than download speeds, so an initial full cloud backup of a large photo or video library can take days rather than hours.
Pro tip: If you're setting up cloud backup for the first time with a large existing library, start the initial backup and let it run overnight or over a weekend rather than expecting it to finish quickly — subsequent backups only need to upload new or changed files, so they're much faster.
Protection Against Different Disasters
This is where the real differences matter, because each option protects against a different set of risks:
| Risk | External Drive | NAS | Cloud |
|---|---|---|---|
| Accidental deletion | Protects (if not deleted from too) | Protects | Protects |
| PC hardware failure | Protects | Protects | Protects |
| Drive itself failing | No protection (unless RAID/second drive) | Some models support RAID redundancy | Protects (provider manages redundancy) |
| Fire, flood, theft at home | No protection if drive is on-site | No protection if kept on-site | Protects (offsite by nature) |
| Ransomware spreading via network | Protects if disconnected when not in use | Vulnerable if always-on and mapped as a drive | Depends on provider's versioning/recovery features |
| Account compromise or provider issues | Not applicable | Not applicable | Vulnerable |
This table makes the case for combining methods obvious: an external drive protects against most day-to-day mistakes cheaply, but does nothing for a house fire; cloud backup solves the fire/theft problem but depends on a company staying in business and your account staying secure; NAS sits in between, offering strong on-site protection with some models supporting RAID redundancy against individual drive failure, but still vulnerable to physical disasters unless paired with off-site cloud sync.
Ease of Use and Maintenance
External drives require the most manual discipline — you need to remember to connect them and run backups, unless paired with scheduling software like File History. They're also the easiest to understand and troubleshoot for non-technical users.
NAS devices offer the most "set and forget" convenience for a household — once configured, every device on the network can back up to it automatically, and many models support scheduled backups from multiple PCs, phones, and even other cloud accounts. The trade-off is a steeper initial setup, including some networking knowledge and periodic firmware updates.
Cloud backup is generally the easiest to set up (install an app, sign in, done) and requires the least ongoing maintenance, since the provider handles the infrastructure entirely. The ongoing subscription cost is the main friction point.
Security and Privacy Considerations
- External drives are entirely under your physical control, which some people prefer for sensitive documents, but this also means physical theft is a direct data breach unless the drive is encrypted (see BitLocker To Go).
- NAS devices, especially if configured for remote access over the internet, need careful attention to firmware updates and strong passwords — an insecurely configured NAS exposed to the internet is a genuine target for attackers.
- Cloud providers invest heavily in infrastructure security, but you're trusting a third party with your data and depending on their policies (check where your data is physically stored and their encryption practices) and on your own account security — enable two-factor authentication on any cloud backup account without exception.
Warning: Whichever method you choose for off-site protection, never leave a NAS's remote-access ports directly exposed to the internet without a VPN or the manufacturer's secure remote-access service — misconfigured NAS devices are regularly scanned and targeted by automated attacks looking for weak or default credentials.
A Practical Recommendation
For most UK households, the strongest and most cost-effective approach combines two of the three:
- An external drive for fast, cheap, everyday backups using File History or similar — your primary defence against accidental deletion and drive failure.
- Cloud backup for your most irreplaceable files (photos, financial documents, important work) as off-site protection against fire, flood or theft.
Add a NAS to this mix once your storage needs grow beyond what one external drive comfortably handles, once you have multiple family members' devices to back up centrally, or once you want automated redundancy without relying solely on a subscription service. A NAS is a genuine upgrade in convenience and control, but it's an investment worth making once you understand your needs, not necessarily the first step.
Decision Checklist
- Budget-conscious, single PC: external drive plus a free-tier cloud service for critical files.
- Multiple devices in one household: NAS as the central hub, with cloud sync for the most important shared folders.
- Maximum protection regardless of cost: all three, following the full 3-2-1 rule — local drive, NAS or second local copy, and cloud.
- Frequently travelling or working from multiple locations: cloud backup as the primary method, since it's accessible from anywhere without carrying hardware.
There's no universally "best" backup method — only the right combination for your budget, your data volume, and how much convenience versus control you want. Whatever you choose, the method that matters most is the one you'll actually keep running.
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