Expansion is Seagate's value line and the direct answer to WD Elements: a drive, an enclosure, a cable, and nothing else. The two lines chase each other on price at most capacities, which is why we compare them directly.
7 in-stock listings · ranked by cost per terabyte
Best cost per terabyte here right now: Seagate Expansion 24TB Portable HDD at $28.33/TB ($680 for 24TB, portable hdd, new listing). We have not found a maker document naming the drive inside it.
| Model | Capacity | Family | Market Value | Historical Value | Interface | Inside | Warranty | Condition | $/TB | Price | Buy |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Seagate Expansion 24TB Portable HDD | 24TB | Portable HDD | GREAT PRICE | USB 3.0 | NOT SOURCED | — | NEW | $28.33 | $680 | Buy on Amazon | |
| Seagate Expansion 22TB Desktop HDD | 22TB | Desktop HDD | FAIR PRICE | USB 3.0 | NOT SOURCED | — | USED | $36.77 | $809 | Buy on Amazon | |
| Seagate Expansion 24TB Portable HDD | 24TB | Portable HDD | In progress | USB 3.0 | NOT SOURCED | — | USED | $37.46 | $899 | Buy on Amazon | |
| Seagate Expansion 6TB Portable HDD | 6TB | Portable HDD | FAIR PRICE | USB 3.0 | NOT SOURCED | — | NEW | $38.96 | $234 | Buy on Amazon | |
| Seagate Expansion 20TB Portable HDD | 20TB | Portable HDD | In progress | USB 3.0 | NOT SOURCED | — | NEW | $40.51 | $810 | Buy on Amazon | |
| Seagate Expansion 4TB Desktop HDD | 4TB | Desktop HDD | In progress | USB 3.0 | NOT SOURCED | — | USED | $43.99 | $176 | Buy on Amazon | |
| Seagate Expansion 1TB Portable HDD Priced far above this family's typical rate | 1TB | Portable HDD | HIGH PRICE | USB 3.0 | NOT SOURCED | — | NEW | $241.63 | $242 | Buy on Amazon |
Market Value compares current listings in the same external-drive family and condition. Historical Value uses stored observations for the exact product condition in the background. For “Inside” we have not found a maker document naming the drive in any of these products, and the contents vary by batch, so we state that rather than guessing — see what the community has found by opening them. Warranty shows a dash because the makers' warranty pages did not resolve through our source-verification path; read the term on the maker's page for the exact model. Interface is the maker's own specification string, not a speed measurement.
Expansion exists to be the cheapest external Seagate sells, and it succeeds at that by removing everything removable. No bundled backup software worth the name, no encryption, no software-defined features — an enclosure with a drive in it and a USB cable in the box.
The line runs in both formats. Expansion Desktop is a 3.5-inch drive with a power adapter, reaching the top of Seagate's external capacity range and delivering the lowest cost per terabyte in their lineup. Expansion Portable is a 2.5-inch bus-powered drive with a much lower ceiling. Seagate does not always make the distinction obvious in listing titles, so the family column below is the reliable place to check.
The competitive picture is unusually simple: Expansion and WD Elements are the same product category at the same market position from the two remaining hard drive manufacturers, and they undercut each other capacity by capacity depending on stock. Neither has a durable advantage, which is why our Elements versus Expansion comparison computes the gap live rather than picking a winner in prose.
Above Expansion sits One Touch, which adds the software, the encryption and a Rescue Data Recovery entitlement. That is the same tiering Western Digital applies, at similar spacing, for similar reasons.
We have not found a Seagate document naming the bare drive inside an Expansion, at any capacity. The enclosure is a product; the drive inside it is a component Seagate reserves the right to source however it chooses.
The community opens these regularly and reports what it finds, and those reports differ across batches of the same model. That is exactly what you would expect from a value product built to a price against a fluctuating supply of drives, and it is why we carry those findings as community reports on the shucking page rather than reproducing them here as facts about what you will receive.
There is a specific reason to care in this line's case. Seagate's value externals are frequently cited in shucking discussions alongside Elements, and the desktop capacities sit at a cost per terabyte where the trade can be genuinely worthwhile. The shuck table on our external drives hub computes the current gap against the cheapest bare drive at each capacity, which is the input that decides it.
Every recording-technology cell below reads 'not sourced', and that will not change until we find a Seagate document that names it. If knowing before you buy matters, buy a bare drive whose recording technology is sourced — our CMR versus SMR list is the lookup.
The reason to buy Expansion rather than something above it comes down to a question worth asking honestly: what would the extra tier actually give you that you would use? Backup software you already have from your operating system, encryption you may or may not need, a case nobody looks at, and on Seagate's upper tier a data recovery entitlement that is genuinely valuable if the drive holds the only copy of something and worth nothing if it does not.
For a second copy in a proper backup arrangement, none of that applies and the saving is free. For a drive that holds the only copy of a decade of photographs, the recovery entitlement on One Touch is the one feature in this whole category worth paying a premium for, and we would rather say that plainly than pretend the value line is always correct.
The other real consideration is capacity. Expansion Desktop reaches the top of Seagate's external range, and buying a rung above what you think you need is usually cheaper per terabyte and always cheaper than replacing a drive that filled. Storage requirements do not shrink, and an external that ran out is a purchase you make twice.
One practical note about the desktop units specifically: they need a mains socket, they are not designed to be moved while running, and a spinning drive that gets knocked mid-write fails abruptly rather than gracefully. If the drive is going to travel at all, buy the portable version and accept the higher rate per terabyte. Our travel guidance covers what actually matters for a carried drive.
Where this line ends up for most people is as the default answer: the cheapest way to add storage that plugs into a USB port, from a manufacturer with a real support operation behind it, with the honest caveat that we have not found a maker document naming what is inside. Our external drives hub ranks it against every other family we track.
Same category, same market position, different manufacturer. Both are barebones externals sold on price with no bundled software, and both come in desktop and portable formats. Neither publishes what drive is inside. They undercut each other capacity by capacity depending on stock, which is why our Elements versus Expansion comparison computes the gap live.
We have not found a Seagate document naming it, and community teardowns show the contents vary between production batches of the same model number. The community documents what it finds by opening them and our shucking guide links that work as the batch-varying reports it is. Any article stating the contents as a specification is asserting something the manufacturer does not.
One Touch is the tier above: it adds backup software, password protection with hardware encryption on most units, and a Rescue Data Recovery entitlement. Expansion has none of those and is priced accordingly. If your operating system already handles backups and the drive lives on a desk, the Expansion saving costs you nothing you were using.
Yes, and it is a physically different product from the desktop version despite the shared name. Expansion Portable is a 2.5-inch bus-powered drive with a considerably lower capacity ceiling and a higher cost per terabyte. Expansion Desktop is 3.5-inch with its own power adapter. The family column separates them.
The column shows a dash because Seagate's warranty pages did not resolve through our source-verification path, and a marketplace listing's claim is not a manufacturer specification. Read the term on Seagate's page for the exact model. Opening the enclosure ends the external warranty in any case.
It is one of the two lines people shuck most, along with Elements, because the desktop capacities land at a cost per terabyte where the trade can be worth it. What decides it is the gap at your capacity today, which the shuck table on our hub computes against the cheapest bare drive in stock.
Specification claims on this page were checked against the pages below on 4 August 2026. Where a widely-repeated figure did not survive that check, we report what the source says now and say so in the text rather than repeating the familiar number.