Choose a portable HDD when large local backup capacity matters most and slower transfers are acceptable; choose a portable SSD when you regularly copy large files, carry the drive or need specified protection against knocks. Pick capacity around the files you plan to protect, future growth and backup history, then check the laptop port, supplied cable and required file format. For important files, keep a separate cloud or off-site copy rather than relying on one device alone.
For people protecting documents, photos and personal folders who need enough room for future backup versions. Apple and Microsoft both support using external storage with their built-in Mac and Windows backup tools, subject to the intended format and setup.
For media libraries that are filling laptop storage and need a choice between capacity-led HDD storage and faster portable SSD transfers. Which? distinguishes HDDs used for long-term file backup from typically faster, pricier SSDs.
For anyone moving an external drive between home, work, study or travel locations. Compact size, compatible ports and cables, plus any model-specific protection rating, deserve particular attention.
Start with the size and type of backup you need, then confirm connection and formatting requirements before choosing portability features.
| Priority | What to check | Your needs |
|---|---|---|
| Backup capacity | Compare the drive size with the folders to be backed up, expected media growth and retained versions. For Time Machine, Apple recommends storage of at least twice the Mac’s capacity. | I want room for my current files as well as later photo and video growth. A dedicated backup volume can help prevent unrelated files from consuming that space. |
| HDD or SSD | Choose an HDD for capacity-focused archives and an SSD for frequent large-file transfers. Compare performance figures within the same storage category and check the test or stated measurement basis. | My drive will either sit mostly at a desk for scheduled backups or travel with me for active file copying. Which? notes that SSDs are usually faster, while HDDs suit long-term file backup. |
| Ports and formatting | Match the drive cable to the laptop’s USB-A, USB-C or Thunderbolt connection. Check the file system before using the drive with Time Machine, Windows backup or both. | I need a drive that fits my computer without assuming a USB-C-shaped connector guarantees full speed. Apple says a Windows-formatted disk must be reformatted before Time Machine can use it. |
| Portability and protection | Check the exact model’s size, weight, drop or ingress rating, and any encryption feature. Read the conditions behind protection claims rather than treating them as cover for every accident. | I may carry private files outside the home, so I want a manageable drive and a second copy stored elsewhere. A rugged case does not replace an off-site or cloud backup. |
Backup tools may retain versions over time, so a drive shared with unrelated files can fill sooner than expected. Apple recommends a Time Machine disk with at least twice the Mac’s storage capacity and advises using it only for Time Machine backups.
Measure the folders you intend to protect, allow for photo and video growth, and consider a dedicated backup volume where practical.
A connector can fit while the laptop, cable or protocol still limits transfer speed. Samsung says its maximum T7 speeds require USB 3.2 Gen 2 host and cable support, with UASP enabled.
Check the actual laptop port specification and the cables supplied with the exact drive. For overnight backups, capacity and backup planning may matter more than an unused headline speed.
Apple states that reformatting a Windows-formatted disk for Time Machine permanently removes the existing data. Western Digital also says its My Passport line is NTFS out of the box and needs reformatting for macOS use.
Copy existing files to another location before changing the file system, then decide whether the drive will be dedicated to Time Machine, Windows backup or cross-platform transfer.
Protection claims have conditions and do not guarantee cover for every loss or accident. Samsung says its T7 Shield environmental resistance is tested under controlled conditions and excludes liquid, dust and drop damage from warranty coverage.
Keep another copy in a separate location, such as another external drive or cloud service, and use encryption or password protection where the exact model supports it.
Relevant for portable and desktop HDD options, including My Passport models for laptop backup and portable capacity.
Relevant for compact portable SSDs where faster transfers, USB-C connectivity and travel-oriented protection are priorities.
Relevant for capacity-focused portable HDD options marketed for routine photo, document and laptop backup.
These Joybuy options focus on portable SSDs for faster local copies and a capacity-led portable HDD for larger photo, document and archive backups.
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For larger photo, video and document libraries that also need frequent large-file transfers.
Stated 4TB capacity, USB 3.2 Gen 2, sequential speeds up to 1,050 MB/s read and 1,000 MB/s write, AES 256-bit hardware encryption, and USB-C-to-C and USB-C-to-A cables.
Maximum stated speeds require a compatible USB 3.2 Gen 2 host connection; check the laptop port and cable setup before expecting the headline rate.
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For a growing backup set shared between compatible laptops, mobile devices and cameras.
Stated 2TB capacity, USB 3.2 Gen 2, speeds up to 1,050 MB/s read and 1,000 MB/s write, AES-256 encryption software, plus USB-C-to-C and USB-A-to-USB-C cables.
The magnetic attachment is described for compatible iPhone 15 and 16 setups and prevents MagSafe wireless charging while attached.
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For portable backups carried between home, work or travel where specified physical protection is important.
Stated 1TB capacity, USB 3.2 Gen 2, sequential speeds up to 1,050 MB/s read and 1,000 MB/s write, IP65 resistance and up-to-3 m drop resistance.
1TB may not cover a full laptop backup plus multiple historical versions, and physical protection does not replace a second backup copy.
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For personal photos, documents and active media libraries needing portable SSD transfer speeds.
Stated 2TB capacity, USB 3.2 Gen 2, speeds up to 1,050 MB/s read and 1,000 MB/s write, optional AES 256-bit hardware encryption, and USB-C-to-C and USB-C-to-A cables.
The listing states that it is not waterproof or dustproof, so consider a rugged model for exposed outdoor or higher-risk travel use.
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For capacity-led home backup of large photo libraries, documents and archives.
Stated 5TB capacity, USB 3.2 Gen 1 Type-C connectivity, AES 256-bit hardware encryption, password protection, a USB-C cable and USB-C-to-USB-A adapter.
It is pre-formatted for Windows and requires reformatting for macOS use according to the listing. As a mechanical HDD, avoid moving or jolting it during transfers.
Apple recommends a storage device with at least twice the storage capacity of the Mac for Time Machine. That is a Time Machine guideline rather than a universal rule for every manual copy or Windows backup, so also allow for the files and backup history you intend to keep.
Yes. Microsoft says File History in Windows 11 and Windows 10 can save backups to an external drive or network location and covers libraries such as Documents, Pictures, Videos and Music. Add other important folders to a library if they also need protection.
Not as a straightforward shared Time Machine volume. Apple says Time Machine cannot back up to a Windows-formatted disk, and reformatting permanently removes its data; preserve existing files first and check whether separate volumes or drives suit your intended setup.
No. Samsung says maximum T7 and T7 Shield sequential speeds require a host device and connection cable supporting USB 3.2 Gen 2, with UASP enabled. Check the computer port, supplied cable and exact model specification before paying extra for higher-speed storage.
Use an appropriate electrical recycling route rather than disposing of it with general waste. GOV.UK’s WEEE guidance covers electrical and electronic equipment, and Recycle Your Electricals advises formatting external media such as hard drives or memory cards before donating, selling or recycling them.