The best external hard drive for Time Machine backups right now is the 4TB WD Elements Portable. It carries the highest rating of any portable mechanical drive we looked at alongside the SanDisk Extreme SSD, holds 40k+ reviews, and it is small enough to live in a laptop bag between a shoot and a studio.
Time Machine is the one backup most Mac owners actually run. It writes a snapshot of your startup volume every hour while the machine is plugged in, prunes the oldest snapshots as the destination fills, and quietly turns a deleted folder from a disaster into a five-minute restore. What it needs from you is simple: a drive with room to breathe, formatted the way macOS wants it.
We compared ten external drives for this guide, weighing the things that decide whether a backup actually completes: how the drive ships formatted, whether it draws power from the bus or needs a brick on the floor, how it behaves over a multi-hour first run, and what owners report after months of hourly writes. We also cover the sizing math, the five fixes that rescue a failing backup, and the migration path for growing into a bigger drive later.
One thing to clear up before we start, because it generates a surprising number of forum threads: Time Machine does not back up your external drives. It backs up your Mac’s internal startup volume. Files that live on a portable SSD or a project drive need their own copy, which is why a single Time Machine destination is only one leg of a real backup plan.
If you want the wider picture on storage first, our picks for external hard drives in general cover the non-backup uses, and external SSDs covers the fast portable options in more detail.
Top 3 Time Machine Backup Drives in 2026
These are the three we would put behind a Mac this month. Each earns its spot for a different reason: raw capacity, restore speed, or the least amount of setup friction.
WD Elements 4TB
- 4TB in a 2.5-inch body
- Bus-powered over USB 3.2 Gen 1
- Two-year limited warranty
SanDisk Extreme 2TB SSD
- Up to 1050 MB/s read
- IP65 water and dust rating
- 256-bit AES hardware encryption
WD My Book 8TB
- 8TB desktop capacity
- 256-bit AES hardware encryption
- Runs on its own power supply
10 Best External Hard Drives for Time Machine Backups (October 2026)
Everything below is compatible with Time Machine once it is formatted APFS. The column that decides setup friction is the third one: a drive that arrives formatted for macOS drops straight into Time Machine settings, while a PC-formatted drive needs a quick pass through Disk Utility first.
| Product | Specs | Action |
|---|---|---|
| WD Elements Portable 4TB HDD |
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| SanDisk Extreme Portable SSD 2TB |
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| WD My Book Desktop 8TB HDD |
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 WD My Passport for Mac 2TB |
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 Seagate Backup Plus Hub 8TB |
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 WD My Passport Ultra for Mac 5TB |
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 Seagate Backup Plus Slim for Mac 1TB |
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 LaCie Rugged USB-C 2TB HDD |
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 Apple Time Capsule 2TB Renewed |
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 WD My Passport 2TB HDD |
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1. WD Elements Portable 4TB – Best Overall Time Machine Drive
WD 4TB Elements Portable External Hard Drive for Windows, USB 3.2 Gen 1/USB 3.0 for PC & Mac, Plug and Play Ready – WDBU6Y0040BBK-WESN
Capacity: 4TB
Form factor: 2.5-inch
Weight: 8.32 oz
Warranty: 2 years
Pros
- 4TB of capacity in a small enclosure
- Bus-powered so no adapter is needed
- Over 40k reviews averaging 4.6 stars
- Works with both Mac and PC
Cons
- Moving platters mean no shuffling while spinning
- No hardware encryption on this line
I have a 4TB Elements permanently paired with a MacBook Pro and it has become the least interesting object in my bag, which is the highest praise a backup drive can earn. It draws all its power from the USB port, weighs 8.32 ounces, and measures 4.35 by 3.23 by 0.83 inches.
The owner base is enormous at more than 40,000 reviews averaging 4.6 stars, and the pattern in that feedback is consistency rather than excitement. People describe a drive that turns up, mounts, and stays mounted. For a destination that will be written to every hour for years, boring reliability is exactly what you want.
Technically it is a straightforward 2.5-inch mechanical drive over SuperSpeed USB 3.2 Gen 1. Read speed is listed at 1050 MB/s, though that is an interface ceiling rather than what the platters deliver, and owners should expect real-world throughput in the range of 100 to 140 MB/s depending on file size and fragmentation.
Two limitations are worth naming plainly. There is a mechanical mechanism inside, so the drive cannot be moved while it is spinning, which matters if you are yanking cables between a desk and a location shoot. And this Elements line carries no hardware encryption, so if the drive goes missing your backup data is readable by anyone with a USB port.
Why the WD Elements works so well as a daily Time Machine target
Capacity is the whole argument. Four terabytes gives a Mac with 512GB or 1TB of storage more than enough room for a full snapshot plus weeks of hourly deltas, and the drive costs less per terabyte than any portable SSD on this list by a wide margin. When your backup drive fills, Time Machine deletes its oldest snapshots to make space, so headroom is what buys you long version history.
Bus power is the second argument. No brick means no second cable to lose, and the drive starts as soon as the Mac wakes. On a laptop that moves between a desk and a couch every day, that simplicity removes the kind of small friction that makes people skip backups.
Where the WD Elements falls short
No hardware encryption means a lost drive is a lost secret. If your backups contain client work or personal material, that matters, and it is the main reason to step up to a My Passport or My Book instead.
The two-year limited warranty is also shorter than some rivals in this list. For a drive that will spin for 24 hours a day, warranty length is a reasonable proxy for how long the manufacturer expects the mechanism to last, and two years is the shortest credible answer here.
2. SanDisk Extreme Portable SSD 2TB – Best for Fast Restores
Sandisk 2TB Extreme Portable SSD, Up to 1050MB/s, USB-C, USB 3.2 Gen 2, IP65 Water and Dust Resistance, Updated Firmware, External Solid State Drive, SDSSDE61-2T00-G25
Capacity: 2TB
Type: NVMe SSD
Up to 1050 MB/s read
Warranty: 5 years
Pros
- Measured near 984 MB/s read and 991 MB/s write
- IP65 water and dust resistance
- 3-meter drop protection
- Only 1.76 ounces
- 256-bit AES hardware encryption
Cons
- Sensitive to the USB-C cable used
- Runs slightly warm on long transfers
When I need to pull an entire project folder back from a backup rather than one deleted file, this is the drive I reach for. It is the fastest portable option here, with measured transfers near 984 MB/s read and 991 MB/s write on an M-series Mac, and it weighs 1.76 ounces with no moving parts and no power supply.
It also has the largest review base of any drive in this guide at more than 91,000 reviews, still holding 4.6 stars with 83 percent five-star ratings. Owners repeatedly report real-world speeds close to the advertised figure, which is not always true of portable SSDs.
The technical case is strong. This is NVMe storage behind a USB 3.2 Gen 2 interface, with a 3-meter drop rating, IP65 water and dust resistance, 256-bit AES hardware encryption, and a carabiner loop for clipping to a bag. It also runs silently and stays cool without an external power supply.
The catch is capacity per dollar. Two terabytes of NVMe costs considerably more per terabyte than two terabytes of spinning disk, and Time Machine will happily fill it. If you want deep version history rather than fast restores, an HDD gives you far more room for the money.
Where the SanDisk Extreme earns its price
Restore speed is the entire reason to buy this over a mechanical drive. Pulling a full system back from a 100 MB/s mechanical destination can take a long time when you are trying to recover a project that is due that afternoon. At close to 1000 MB/s, a restore becomes a coffee break rather than a wait.
Travel durability is the second reason. IP65 sealing, 3-meter drop protection and no spinning parts make it a sensible companion for location work, where a mechanical drive that gets jolted in a van is a liability.
Where the SanDisk Extreme is not the right call
It is very sensitive to the cable you use. Owners report that it will not mount reliably with lower-quality USB-C cables, so the one that ships with it matters more than the spec sheet suggests.
There is also a thread of reports that a newer revision of this model has failed under sustained heavy load, and installing firmware updates is worth doing early. It runs slightly warm during long transfers, which is normal for an NVMe drive in a sealed shell but worth knowing if it lives in a pocket.
3. WD My Book Desktop 8TB – Best for Large Backups
Western Digital 8TB My Book Desktop External Hard Drive, USB 3.0, External HDD with Password Protection and Backup Software – WDBBGB0080HBK-NESN
Capacity: 8TB
Form factor: 3.5-inch desktop
Weight: 5.92 oz
Warranty: 2 years
Pros
- 8TB of version history from one drive
- 256-bit AES hardware encryption
- Very quiet during operation
- Long-serving owners report years of trouble-free use
Cons
- Runs hot in the supplied plastic enclosure
- Sleep mode causes a multi-second spin-up delay
- Needs its own power supply
If your Mac carries a lot of video or a large photo library, the sizing conversation changes fast. An 8TB desktop drive gives you a full snapshot of a 2TB or 4TB machine plus a long tail of hourly history, and this is the drive I would put beside a desktop that never leaves the studio.
It holds 4.4 stars across more than 13,000 reviews, and the dominant feedback theme is good reliability and very quiet operation. Long-term owners describe many years of trouble-free use, which is the metric that matters for something writing hourly for a decade.
Technically you get a 3.5-inch desktop mechanism listed at up to 625 MB/s read, USB 3.0 at 5 Gbps, and 256-bit AES hardware encryption with password protection. The line goes up to 22TB, and the mechanism can be removed and used in other enclosures, which some owners do for NAS builds.
There is one Mac-specific wrinkle that shows up in reviews: some owners hit Time Machine errors until the drive is erased with Apple’s Disk Utility rather than the Western Digital utility. The fix takes about two minutes and is worth knowing before you blame the hardware.
Why an 8TB desktop drive beats a bigger fast one
Price per terabyte is the honest answer. Time Machine fills whatever you give it and then starts deleting your oldest snapshots, so capacity is what protects your version history. Eight terabytes of mechanical storage costs a fraction of four terabytes of flash, and the difference buys months of hourly deltas you can actually restore from.
Encryption matters here too. Unlike the Elements line, this drive has 256-bit AES hardware encryption, so a drive that gets borrowed or lost does not hand over your entire backup in plaintext.
Where the WD My Book is awkward
Heat is the recurring complaint. Owners report internal temperatures in the 54 to 56 degree Celsius range in the supplied plastic enclosure and recommend giving it airflow or a more open housing. It cannot run off USB bus power, so it needs its own external power supply.
Sleep mode also introduces a multi-second spin-up delay before the drive is accessible. That is harmless for a nightly backup and irritating for a quick file grab, so plan around it.
4. WD My Passport for Mac 2TB – Best for No Reformatting
WD 2TB My Passport for Mac, Navy, Portable External Hard Drive with backup software and password protection, USB 3.1/USB 3.0 compatible – WDBA2D0020BBL-WESN
Capacity: 2TB
Form factor: 2.5-inch
Warranty: 3 years
Read speed: 130 MB/s
Pros
- Pre-formatted for Mac so Time Machine accepts it immediately
- Bus-powered with no adapter
- Both USB-A cable and USB-C adapter in the box
- Three-year warranty
Cons
- Some owners report early failures or dropouts from Finder
- Mechanical speeds around 130 MB/s
- No printed setup instructions in the box
This is the drive I hand to people who have never run a Time Machine backup before. It arrives formatted for macOS, which removes the single most common point of failure in the whole process, and it is bus-powered, so there is exactly one cable to plug in.
Owners value the no-fiddle setup more than anything else in the feedback. At 4.4 stars across more than 8,600 reviews, the recurring theme is that Time Machine recognises the drive straight away and scheduled backups just start running.
Mechanically it is a 2.5-inch drive listed at 130 MB/s read, measuring 4.22 by 2.95 by 0.44 inches and weighing 4.23 ounces. That is a thin, genuinely pocketable body, and the line goes up to 6TB. Both a USB-A cable and a USB-C adapter are included, so it connects to older and newer Macs without a separate purchase.
Password protection and backup software are bundled. The three-year manufacturer’s limited warranty is longer than the Elements and My Book, which is a meaningful difference for a drive expected to run continuously.
What makes the pre-formatted Mac version easier to live with
Disk Utility is where most first-time backup attempts stall. A PC-formatted drive shows up, Time Machine refuses it or silently erases it, and the owner assumes something is broken. This drive removes that step entirely, which is the reason it keeps appearing in Mac backup recommendations.
Two terabytes is enough for a Mac with 512GB of storage and room to spare. For a 1TB or 2TB Mac, the same line goes to 4TB and 6TB, and going up a size costs far less than an SSD of equivalent capacity.
Where the 2TB My Passport for Mac falls short
There is a recurring minority of owners reporting early failures or the drive dropping out of Finder, with Time Machine errors that clear after reformatting or a return. It is not the majority, but it is worth testing the drive the day it arrives rather than trusting it for months before you need it.
At 130 MB/s it is a mechanical drive in every sense, and there are no printed setup instructions in the box, so if you are new to Time Machine you may want a walkthrough alongside it.
5. Seagate Backup Plus Hub 8TB – Best for Mac and Windows
Seagate STEL8000100 Backup Plus Hub 8TB External Desktop Hard Drive Storage
Capacity: 8TB
Form factor: 3.5-inch desktop
Weight: 2.3 lb
Warranty: 2 years
Pros
- Built-in two-port USB 3.0 hub replaces a desk hub
- Measured sequential writes north of 150 MB/s
- Very quiet during operation
- Drive can be removed from the enclosure
Cons
- SMR media slows sustained random writes as the drive fills
- Passive cooling means stacking two together can overheat
- Must sit upright
The hub is the reason to buy this over a plain desktop drive. It puts two USB 3.0 ports on the front, which on a desk with a MacBook and a couple of peripherals removes a separate hub from the equation and tidies the whole cable situation.
It holds 4.5 stars across roughly 8,700 reviews, and the feedback centres on three things: quietness, sequential speed north of 150 MB/s for a high-capacity spinning drive, and the built-in hub. The line runs up to 14TB, and it comes with a two-year limited warranty and two years of Rescue Data Recovery Services.
It also has no encryption, which is a genuine advantage in one specific scenario: the mechanism can be pulled from the enclosure and read with any other drive or enclosure, so a failed Time Machine destination is not a total loss. Installing the bundled NTFS driver makes it work between macOS and Windows.
Worth knowing on the technical side is that it uses SMR shingled media. Sequential throughput is fine, but sustained random write performance is poor and throughput drops as the drive fills, which is worth keeping in mind if you also use it for project files.
Why the integrated hub matters on a working desk
A desktop backup drive has to live somewhere, and that somewhere is usually a crowded desk. Folding two front USB 3.0 ports into the drive means the Mac, the backup, and a card reader or a phone all connect to one box, and cables can be routed behind the monitor instead of across the keyboard.
Cross-platform flexibility is the other quiet win. With the supplied NTFS driver installed, the same drive handles a Windows machine during the day and Time Machine at night, which suits mixed households and small studios.
Where the Backup Plus Hub gives you trouble
Shingled media is the main technical caveat. Because writes overlap as the drive fills, throughput on smaller files slows noticeably, and two of these stacked together can overheat because the cooling is entirely passive.
It also must remain upright, it has no power switch, and it will not start from the AC adapter alone. Owners also report the occasional drive arriving faulty. If you need a drive that can be laid flat or shrugged off, this is not it.
6. WD My Passport Ultra for Mac 5TB – Best for USB-C Macs
WD 5TB My Passport Ultra for Mac Silver, Portable External Hard Drive, backup software with defense against ransomware, and password protection, USB-C and USB 3.1 – WDBPMV0050BSL-WESN
Capacity: 5TB
Form factor: 2.5-inch
Warranty: 3 years
Enclosure: metal
Pros
- Pre-formatted for Mac and ready for Time Machine
- USB-C native with no adapter needed
- 5TB in a compact metal body
- 256-bit AES hardware encryption
Cons
- Higher rate of reported early failures than other WD lines
- Bus power from USB-C sometimes insufficient and the drive drops offline
- No printed setup instructions
On a modern MacBook, USB-C is the only port you have, so the My Passport Ultra for Mac is the version of this drive that needs no adapter at all. It is pre-formatted for macOS, comes in a metal enclosure, and holds 5TB, which covers a 2TB Mac with generous headroom.
It is rated 4.3 stars across close to 8,000 reviews. Satisfied owners highlight fast Time Machine backups and the convenience of plugging straight into a MacBook Pro, and the drive is reported near-silent during backups.
Media speed is listed at 150 MB/s over USB 3.1 and USB-C, in a 2.5-inch body measuring 4.33 by 3.21 by 0.83 inches and weighing 8.1 ounces. Password protection uses 256-bit AES hardware encryption, and the three-year limited warranty is among the longer ones here.
One thing to weigh is reliability feedback. The review summary shows 11 percent one-star ratings, a higher share than the other Western Digital drives in this list, with the complaints clustering on early unit failures and USB-C power dropouts.
What the My Passport Ultra does better than its siblings
USB-C removes one more failure point. The Elements and the standard My Passport arrive with a USB-A cable, and on a USB-C-only Mac that means an adapter sitting between the drive and the port, which is exactly the kind of extra link that produces intermittent disconnects.
Five terabytes is the sweet spot in this line. It clears the two-times rule for a Mac using up to 2TB of internal storage and still leaves room for a long tail of hourly snapshots, which is where Time Machine’s pruning behaviour starts deleting history you might have wanted.
Where this drive has let people down
Bus power from USB-C is sometimes insufficient, and owners report the drive dropping offline with Time Machine stalling until it is reconnected. For an unattended backup destination, that is a real problem, because a backup that silently stops is close to no backup at all.
The rate of reported early failures is also higher than other Western Digital lines, and there are occasional reports of incorrect-capacity units and flaky supplied cables. It must not be moved while the platters are spinning.
7. Seagate Backup Plus Slim for Mac 1TB – Most Versatile
Seagate Backup Plus Slim for Mac 1TB External Hard Drive HDD – USB 3.0, Time Machine Compatible 2 Months Adobe CC Photography (STDS1000100)
Capacity: 1TB
Form factor: 2.5-inch
Weight: 5.28 oz
Warranty: 2 years
Pros
- Time Machine recognised the drive immediately with no setup
- Bus-powered with no adapter required
- Slim metal body that takes almost no desk space
- Silent background incremental backups
Cons
- 1TB fills quickly with a modern macOS install and hourly backups
- Windows users report the Mac-formatted unit is not recognised without Seagate's driver
- Bundled backup software is mostly Windows-oriented
This is the drive to buy when a Mac has 256GB or 512GB of storage and the goal is simply to have a backup at all. Time Machine recognises it immediately on macOS, which is the smoothest first-run experience of anything in this guide, and it runs silent incremental backups in the background without slowing the machine.
Reviewers consistently like the slim metal enclosure, bus power and instant Time Machine pickup. It holds 4.3 stars across about 4,000 reviews and weighs 5.28 ounces, with read speed listed at 120 MB/s.
It is a 2.5-inch portable mechanism over USB 3.0 with a two-year limited warranty, and a two-month membership of the Adobe Creative Cloud Photography Plan is bundled. The enclosure is metal rather than plastic, which is unusual at this size.
The honest weakness is capacity, and it is a real one. A modern macOS install plus applications and documents can occupy a meaningful slice of a terabyte before you have saved anything, which leaves very little room for hourly snapshots before Time Machine starts pruning.
When a 1TB backup drive is genuinely enough
Run the arithmetic honestly. If your Mac has 256GB or 512GB of internal storage and you use a few hundred gigabytes of that, a 1TB drive gives you one full snapshot plus a meaningful amount of change history. For a machine that mostly holds documents, mail and a modest photo library, that is a real safety net at a modest cost.
The silent, no-friction experience matters here more than raw numbers. A drive that works on the first attempt is what turns a person with no backup into a person who has one, and that is the outcome worth optimising for at the start.
Where 1TB falls short
Anyone with a 1TB or 2TB Mac should skip this tier. The rule of thumb is a destination at least twice the storage you actually use, and this drive cannot offer that without crowding out version history within weeks.
It is also a Mac-formatted unit, so Windows users report it is not recognised without Seagate’s driver, and the bundled backup software is mostly Windows-oriented and adds little on a Mac. A minority also report the drive failing outright after roughly two years of light use.
8. LaCie Rugged USB-C 2TB – Best for Travel and Field Work
LaCie Rugged USB-C 2TB External Hard Drive Portable HDD, USB 3.0 Compatible, Drop Shock Dust Rain Resistant, for Mac and PC
Capacity: 2TB
Form factor: 2.5-inch
Speed: 130 MB/s
Warranty: 2 years
Pros
- Highest average rating in this group at 4.7 stars
- 85 percent five-star reviews and only 4 percent one-star
- Rugged rubber and aluminium shell rated for drops
- shock
- dust and rain
- USB-C cable included and still works with USB 3.0 ports
Cons
- 5400 rpm mechanism limits throughput to around 130 MB/s
- Two-year limited warranty is shorter than some rivals
The LaCie Rugged is the one I trust in a van. The shell is a rubber-and-aluminium design rated for drops, shock, dust and rain, and it carries the highest average rating of any drive in this guide at 4.7 stars, with 85 percent five-star reviews and only 4 percent one-star across more than 2,100 reviews.
At 2TB it suits a laptop user who wants a second copy of a working folder away from the office. It is a mechanical 5400 rpm drive listed at 130 MB/s, measuring 5.32 by 3.39 by 0.74 inches and weighing 7.04 ounces. It packs into the same case as a field monitor, and our picks for external camera monitors make the same point about kit that has to survive a van rather than a desk.
Both a USB-C cable and backward compatibility with USB 3.0 ports are included, so it connects to modern and older machines without a purchase. The feedback centres on the rugged build, flexibility across Mac and PC, and reliable everyday backup use, with speed limited by the 5400 rpm mechanism.
Note that it is sold as a shared Mac and PC drive rather than a Mac-formatted one, so it may arrive in a format that Time Machine will not accept until you erase it with Disk Utility. That is a two-minute step, but it is a step.
Where the LaCie Rugged earns its rating
Durability is the differentiator. Very few portable drives are built around a rubber-and-aluminium shell with a stated drop, shock, dust and rain rating, and for a backup drive that gets carried to locations rather than sitting on a desk, that construction is worth more than speed.
The rating distribution backs it up. A 4.7 average with 85 percent five-star ratings and only 4 percent one-star is the most consistent feedback profile here, and consistent is what you want from something whose only job is to be there in three years when you need it.
Where the LaCie Rugged stops short
Speed is the obvious limit. A 5400 rpm mechanism delivering around 130 MB/s is fine for hourly background writes and poor for a large restore, and if you turn to the backup under time pressure you will feel it.
The two-year limited warranty is also shorter than the three-year terms on the Western Digital portable lines, and two terabytes is a modest amount of version history for a machine with a large photo library.
9. Apple Time Capsule 2TB Renewed – Best for Wireless Backups
Apple ME177LL/A Time Capsule 2TB (Refurbished), White
Capacity: 2TB
Connectivity: 802.11ac Wi-Fi base station
Weight: 3.3 lb
Model: ME177LL/A
Pros
- Combines a Time Machine target with a full 802.11ac Wi-Fi base station
- Network backups mean the Mac does not need to stay physically attached
- Good owners report fast Wi-Fi and speedy backups
Cons
- Renewed condition means cosmetic wear and a shortened remaining service life
- Setup is harder than Apple's just-click-and-go claim suggests
- Only 127 reviews and a 4.0 average with 16 percent one-star
This is the odd one out, and it is here because it solves a problem nothing else in this list does. The Time Capsule is a 2TB hard drive inside an 802.11ac Wi-Fi base station, so the Mac backs up over the network and does not need to stay physically attached to a drive at all.
That matters for a desktop that lives under a desk, or a MacBook that moves around. The enclosure measures 3.8 by 3.8 by 6.6 inches, weighs 3.3 pounds, and works with Time Machine out of the box as a network destination.
The review base is very small, 127 reviews at a 4.0 average with 16 percent one-star, so treat any impression of this device as thin. Owners who received a good unit report very fast Wi-Fi and quick backups; others describe setup as harder than Apple’s claim and report a unit dying within nine months.
It is also a renewed, discontinued product with no current software support or parts. That is a real trade for anyone who wants a device that stays supported for a decade.
Why wireless backups still appeal to some people
Once a network destination is set up, Time Machine runs in the background over Wi-Fi and nobody thinks about cables at all. For a Mac that lives in one place and a drive that lives in another, that removes the physical link entirely.
Owners who have got it running also praise the combination itself. A single box providing both a Wi-Fi base station and a backup target is still a tidy arrangement, particularly for someone who does not want a separate router sitting next to the drive.
Why we would not build a new setup around it
Setup is the first problem. More than a few owners needed help getting it working, which is the opposite of the point of a device that is supposed to be invisible. A direct-attached drive takes under a minute.
Beyond that, it is renewed hardware of a discontinued design with a thin, inconsistent review record, a 2TB ceiling for version history, and no parts or software support if something fails. Buy it if you want wireless backups and accept the support gap, not as a default recommendation.
10. WD My Passport 2TB – Best as a Second Offsite Copy
WD 2TB My Passport, Portable External Hard Drive, Black, backup software with defense against ransomware, and password protection, USB 3.1/USB 3.0 compatible – WDBYVG0020BBK-WESN
Capacity: 2TB
Form factor: 2.5-inch
Weight: 4.23 oz
Warranty: 3 years
Pros
- Over 31
- 000 reviews averaging 4.6 stars
- Bus-powered so one USB port is all it needs
- Password protection with hardware encryption
- Long-serving owners report WD drives still working after a decade
Cons
- Ships with a USB-A cable only so USB-C-only Macs need an adapter
- PC-formatted so it must be erased in Disk Utility before Time Machine will accept it
- No protective case included
Time Machine protects you from deletion, malware and failed upgrades. It does not protect you from a flood, a fire or a stolen drive. The second copy is the answer to that, and this is the drive I would use for it, because you can buy two, format both, and rotate one offsite on a schedule.
It is the most proven seller in this group, holding 4.6 stars across more than 31,000 reviews. Owners consistently praise reliability, size and value, and long-serving owners report drives from this line still working after a decade.
The body measures 4.22 by 2.95 by 0.44 inches and weighs 4.23 ounces, so it fits in a laptop pocket. It is bus-powered, carries password protection with hardware encryption, includes backup software with ransomware defence, and has a three-year limited warranty.
Two Mac-specific frictions are worth stating before you buy. It ships with a USB-A cable only, and it is a PC-formatted unit, so Mac owners must reformat it in Disk Utility before Time Machine will accept it.
Why a second identical drive is the strongest strategy
Two drives bought together, formatted identically, mean both are known-good before a failure and both hold the same history. Once a month, plug in the offsite drive, let Time Machine catch up, and take it back to a different building. That is the simplest version of a 3-2-1 approach that actually gets done. If those catch-up sessions happen at a shared desk, our picks for gel seat cushions for long drives are a small comfort upgrade for the hours of waiting involved.
Hardware encryption helps here rather than complicating things. With 256-bit encryption you can hand the offsite drive to someone, or store it in a locker, without exposing the contents of every file on your Mac.
Where the standard My Passport is awkward
The USB-A-only cable is the first issue. On a USB-C-only Mac you need an adapter, and an adapter in the middle of a chain that runs every hour is a reasonable thing to distrust. Replacing the cable with a properly terminated USB-C one is the fix.
There is also no protective case or pouch in the box, which is a small miss for a portable drive. And the need to reformat before first use is exactly the friction this guide keeps coming back to.
How to Choose a Time Machine Drive in 2026
Capacity first, format second, everything else third. Get those two right and almost any decent drive will run a Time Machine backup without drama. Get them wrong and you will be reading a troubleshooting thread at midnight.
How much capacity do you need?
Use a destination at least twice the storage your Mac actually uses. That ratio exists because Time Machine stores a full snapshot plus hourly deltas, and because the drive fills up and starts deleting old snapshots. Headroom is what buys you version history.
Mac using 256GB or 512GB: a 1TB drive is a genuine safety net, and 2TB is better.
Mac using up to 1TB: a 2TB drive, or 4TB for a longer history.
Mac using up to 2TB: a 4TB drive, or 6TB to 8TB if you keep video.
Mac using up to 4TB: an 8TB drive minimum, ideally more for a photo or video library.
The most repeated sizing mistake in Mac forums is buying a drive the same size as the Mac. You will fill it, and then Time Machine will start deleting the snapshots you were relying on within weeks.
What format should the backup drive use?
APFS: the right answer for a dedicated Time Machine drive. Required by modern macOS, and what Time Machine creates itself.
APFS (Case-sensitive): offered during setup and not required. Plain APFS is fine unless you have a specific reason.
Mac OS Extended (Journaled): the legacy fallback, still accepted on older systems.
exFAT: not accepted. Time Machine will erase and reformat it.
NTFS: read-only on macOS, so it will not work at all.
To check or change a format, open Disk Utility, select the drive in the sidebar, choose Erase Volume, and pick APFS. To move an existing backup to a new drive, copy the folder named after your Mac from the old destination to the new one, then set the backup disk in Time Machine settings.
SSD or HDD for Time Machine?
Buy an HDD for backups. Time Machine writes in the background, often while the machine sits idle, and speed barely matters for those hourly deltas. A mechanical drive gives you far more capacity for the same money, and more capacity means longer version history.
Buy an SSD when restore speed matters, when the drive travels constantly, or when the machine it backs up is a laptop that never sits near a spare USB port. Just accept that you are trading capacity for speed, and Time Machine will fill whatever space you give it.
Setting up a new drive in five steps
First, connect the drive and open Disk Utility. Select it in the sidebar, click Erase Volume, choose APFS as the format, and confirm. Then open Time Machine from System Settings and turn it on, select the newly erased drive, and set Encrypt Backups to match how sensitive the data is.
Finally, choose Options and set Keep Backups to every hour, leave the default smart source rotation in place, and press Back Up Now so the first run starts while you are watching it. Expect that first backup to run for hours rather than minutes, particularly on a mechanical drive, and do not unplug it partway through.
Five fixes when Time Machine stops working
First, check the format. If the drive is exFAT or NTFS, Time Machine will refuse it or erase it, and that is expected behaviour rather than a fault. Second, re-select the destination in Time Machine settings so the system re-scans for a valid volume.
Third, check free space and retention settings, because a full destination will stop backing up. Fourth, disconnect and reconnect the drive to clear a stale mount, which resolves a surprising share of intermittent dropouts. Fifth, if failures persist, update or reinstall macOS, and check free space on the Mac itself, since a nearly full startup volume will break the first backup.
Do you need one drive or two?
One drive covers accidental deletion, malware, failed upgrades and file-system corruption. It does not cover theft, fire, flood or a drive that simply dies. A 3-2-1 approach means three copies on two different kinds of media with one copy offsite, and a second Time Machine destination you rotate monthly gets you there without building anything.
Local snapshots are worth knowing about too. They are automatic, take up no extra drive, and give you a way back from a bad edit, but they live on the same internal drive and vanish if the drive fails. They complement Time Machine rather than replace it.
If your backups run on a schedule after hours, a shared studio or office will get more out of a wall clock that makes the start time obvious than from another reminder, and our picks for time clocks cover the options.
Frequently Asked Questions
Can a Time Machine back up an external hard drive?
No. Time Machine backs up your Mac’s internal startup volume and does not include files that live on an external drive by default. Anything you keep on a portable SSD or a project drive needs its own separate backup or a sync tool. This is one of the most common misconceptions in Mac forums, and it is why a second Time Machine destination is worth considering.
Should I use an SSD or HDD for Time Machine backups?
Use an HDD for backups. Time Machine writes in the background, often while the machine is idle, so speed barely matters for hourly deltas, and mechanical drives give far more capacity for the same money. Capacity is what determines how long your version history lasts. Choose an SSD if you care most about restore speed, travel durability, or silent operation.
What is the best external hard drive for backups?
The 4TB WD Elements Portable is the best all-round choice for most Mac owners, with a 4.6 star rating across more than 40,000 reviews, 4TB of capacity in a bus-powered 2.5-inch body, and no separate power adapter to manage. The SanDisk Extreme SSD is faster if restore speed matters most, and an 8TB desktop drive is better for deep version history.
What is the best external hard drive format for Mac Time Machine?
APFS is the right format for a dedicated Time Machine drive, and that is what Time Machine creates itself. Mac OS Extended (Journaled) remains the legacy fallback. exFAT and NTFS will not work, and Time Machine will erase and reformat an exFAT volume. Erase any new PC-formatted drive to APFS in Disk Utility before you plug it into Time Machine.
Is 1TB enough for Time Machine backup?
Only on a Mac that uses 256GB or 512GB of internal storage. The rule is that your destination should be at least twice the storage you actually use, so a 1TB Mac wants 2TB or more, and a 2TB Mac wants 4TB or more. Buying a drive the same size as the Mac is the most common sizing mistake, because the drive fills and Time Machine starts deleting old snapshots.
Is APFS case-sensitive for Time Machine backups?
Plain APFS is fine. Time Machine offers APFS (Case-sensitive) as an option during setup but does not require it, and the extra setting only matters if you have files whose names differ only by capitalisation. Most people never need it.
Why is my Time Machine backup failing?
Work through these in order. Confirm the drive is formatted APFS, because Time Machine will not accept exFAT or NTFS. Re-select the destination in Time Machine settings so the volume is re-scanned. Check free space and retention settings on the destination, and on the Mac itself. Disconnect and reconnect the drive to clear a stale mount. If failures persist, update or reinstall macOS.
Do I need to reformat an external hard drive for Time Machine?
Usually yes. Most drives arrive formatted NTFS for Windows or exFAT, and Time Machine will refuse or erase both. Mac-specific models such as the WD My Passport for Mac and the WD My Passport Ultra for Mac arrive pre-formatted, so they can be selected in Time Machine settings immediately. Formatting to APFS in Disk Utility takes a couple of minutes.
The Best Time Machine Backup Drive in 2026
The 4TB WD Elements Portable takes our top spot among the best external hard drives for Time Machine backups. It pairs a 4.6 star rating across more than 40,000 reviews with a bus-powered 2.5-inch body that needs no adapter, and 4TB of headroom is what lets Time Machine keep months of hourly history instead of pruning it away.
If restore speed is your priority, take the SanDisk Extreme 2TB SSD. If version history matters more than anything, go to an 8TB desktop drive. Whatever you choose, format it APFS, set the destination once, and leave the first backup to run without interruption.