Yes—you can back up many directly connected external hard drives to the cloud, but support depends on the service and plan. In the evidence available for this comparison, Backblaze Computer Backup is the clearest documented fit for attached drives. Its default version history also makes drive reconnection frequency important: a drive that is disconnected for more than 30 days can lose its backed-up data from the backup.
Carbonite lists an eligible option for a computer plus an external drive, subject to plan restrictions. IDrive Personal supports multiple computers with storage-capped plans, but the available product information does not confirm attached external-drive support. Check compatibility and current plan terms before subscribing.
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What to check before choosing cloud backup for an external drive
Do not assume that a service’s “unlimited” positioning means it includes every connected volume. Confirm that the plan covers directly attached USB or other external drives, then check what happens when a drive is unplugged. For drives that are not connected every day, the service’s retention rule can matter as much as its storage model.
- Drive eligibility: Does the service explicitly include directly attached external drives?
- Connection schedule: How often must an intermittently connected drive reconnect to remain in the backup?
- Plan and device limits: Does the eligible tier cover the computer and drive you need, and is storage capped?
- Recovery: Check version retention and available restore methods, not just backup capacity.
The comparison below reflects published documentation and plan descriptions, not hands-on testing. Plan names, features, and terms can change, so verify them on the provider’s current pages before buying.
#1 Best Overall
- Easily store and access 2TB to content on the go with the Seagate Portable Drive, a USB external hard drive
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop
- To get set up, connect the portable hard drive to a computer for automatic recognition no software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
How the documented options compare
| Service | External-drive eligibility | Storage and computers | Connection, retention, or restore details |
|---|---|---|---|
| Backblaze Computer Backup | Official support documentation says external hard drives can be added to Computer Backup. Backblaze support: external hard drives | The official product page describes computer backup and connected external-drive data; it distinguishes NAS backup. Backblaze external-drive backup | With default 30-day version history, reconnect a disconnected drive at least once every 30 days to keep its backed-up data. Missing-drive alerts are sent after 14, 21, and 28 days. The pricing page lists mailed hard-drive restores and a forever file-version retention option; confirm current terms. Backblaze pricing |
| Carbonite | The official personal page lists an option for one computer plus one external hard drive. A March 17, 2026 comparison says external-drive capability is not included automatically on Basic and identifies Plus or Prime; verify current eligibility because tiers can change. Carbonite personal plans · Tom’s Guide comparison, March 17, 2026 | The cited official page lists the computer-plus-drive option; a storage cap is not stated in the cited material. | A reconnection deadline and restore method are not stated in the cited material. |
| IDrive Personal | Attached external-drive eligibility is not established by the cited material. | The official pricing page lists storage-capped Personal tiers for one user and multiple computers. IDrive pricing plans | A reconnection deadline, version-retention detail, and restore method are not stated in the cited material. |
Backblaze: the clearest documented fit for attached drives
Backblaze’s support documentation explicitly says external hard drives can be added to Computer Backup. It advises keeping multiple drives connected simultaneously as much as possible. Under the default 30-day version history, a disconnected drive must reconnect at least once every 30 days or its backed-up data will no longer remain in the backup. Backblaze says it sends missing-drive alerts after 14, 21, and 28 days. See the external-drive support guidance for the provider’s rules.
The product distinction matters: Backblaze’s external-drive information describes computer backup and connected external-drive data, while its product page distinguishes NAS backup and directs NAS customers to B2 Cloud Storage. Do not treat the attached-drive guidance as confirmation that a network-attached storage device is covered by Computer Backup. Backblaze’s product description
Rank #2
- Easily store and access 5TB of content on the go with the Seagate portable drive, a USB external hard Drive
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop
- To get set up, connect the portable hard drive to a computer for automatic recognition software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
The official pricing page lists free mailed hard-drive restores and a forever file-version retention option. These are listed features, not a guarantee that every plan or circumstance has identical terms; check the live page for the current plan details. Backblaze pricing
Recommended Free Tools
Carbonite: check the eligible tier before signing up
Carbonite’s personal plans page lists an option for one computer plus one external hard drive. A March 17, 2026 comparison reports that external drives are not automatically included on Basic and identifies Plus or Prime for those capabilities. Because plan names and eligibility can change, confirm that the specific offer you are considering covers your external drive. Carbonite personal plans · Tom’s Guide comparison, March 17, 2026
Rank #3
- Easily store and access 1TB to content on the go with the Seagate Portable Drive, a USB external hard drive.Specific uses: Personal
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop. Reformatting may be required for Mac
- To get set up, connect the portable hard drive to a computer for automatic recognition no software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
IDrive Personal: a multi-computer option, with a drive-support question to verify
IDrive’s official pricing page describes Personal storage tiers for one user and multiple computers. That can be relevant if you need to protect more than one computer, but the cited page does not establish that its current client backs up external drives attached to those computers. Treat it as a possible option only after checking current product documentation or confirming compatibility with IDrive. IDrive pricing plans
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Pair cloud backup with a separate local copy
Cloud backup and a local drive serve different roles. A cloud copy provides an off-site recovery option; a separate external hard drive can provide a local copy. A March 17, 2026 comparison recommends using both as part of a broader backup strategy. Choose a local drive with enough capacity for the data you intend to copy; no particular model, capacity, interface, or performance level is established here. A local copy is complementary, not a substitute for off-site backup. Tom’s Guide comparison, March 17, 2026
Quick Recap
Best Value
- [Upgraded Version] - This external hard drive features a mirrored logo stripe combined with a striped anti-slip design, and the rounded corners of the casing make it easier to grip. The stripes also have a heat dissipation function, ensuring stable and fast data transfer.
- 【Ultra-thin and quiet】 - The motherboard adopts JMicron 578 noise-free solution, giving you a quiet working environment. Lightweight and portable size designed to fit in your pocket for easy portability.
- 【Ultra-Fast Data Transfers】 - Pairing this external hard drive with JMicron 578 solution USB 3.0 and USB 2.0 interfaces enables blazing-fast data transfer. It boasts theoretical read speeds of up to 125MB/s and write speeds of up to 103MB/s.
- 【Plug and Play】 - With no software to install, just plug it in and the drive is ready to use.The hard disk chip is wrapped with an aluminum anti-interference layer to increase heat dissipation and protect data.
- 【What You Get】 - 1 x Portable Hard Drive, 1 x USB 3.0 Cable, 1 x User Manual, Gift-type shell packaging ,Three-year manufacturer's warranty and free technical support services.
Rank #4
- Easily store and access 4TB of content on the go with the Seagate Portable Drive, a USB external hard drive.Specific uses: Personal
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop
- To get set up, connect the portable hard drive to a computer for automatic recognition no software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
