Backblaze is one of the largest cloud storage companies in the world and the publisher of an annual HDD stats report it has been providing since 2013. The company recently published its 2025 report, so let’s dive into the data and see which drives were the most reliable, and which earned the dubious honor of being the least reliable.
Overall, Western Digital had the most reliable HDDs in 2025
Technically, WD was also the least reliable vendor
Looking at the overall numbers, Western Digital (WDC) had the most reliable HDDs of 2025. Of the five models found in Backblaze’s data centers, only one had a failure rate above 1%: the WUH721816ALE6L0 16TB, at 1.97%. Overall, WDC drives had a failure rate of just 0.86%, which is impressive considering they make up nearly a quarter of Backblaze’s fleet.
WDC was followed by Toshiba, with an average failure rate of 1.86%; HGST, at 2.26%; and Seagate, at 2.41%. While these numbers are excellent across the board, Toshiba was hands down the best of the rest when accounting for scale, since it supplies more than a third of the drives used by Backblaze. Seagate’s drives make up a similar share of the fleet (33.59% vs. Toshiba’s 33.46%), making HGST the worst performer of 2025, as it barely edges out Seagate despite accounting for just 8.04% of Backblaze’s total drive count. Since HGST (formerly Hitachi) is owned by Western Digital, we could say that Western Digital was both the best and worst performer in Backblaze’s data centers in 2025.
No drive achieved a zero failure rate
Only 12 models had a failure rate lower than 1%
When looking at the yearly stats, not a single HDD model managed to snag the 0% failure rate crowning achievement. Some were very close, but every single one had at least one failure.
Looking at the absolute number of failures, only one out of 466 Seagate ST16000NM002J 16TB drives failed throughout 2025. However, given the minuscule sample size, I don’t think this warrants any accolades. The same can be said for the WDC WUH722626ALE6L4 26TB, which also had just one failure, but only 1,201 drives are in operation, and the model has been in use for just one quarter.
Only 12 models in total managed to stay below a 1% failure rate, with WDC coming out on top again. Four of its five models stayed under 1%, which is impressive considering there are 31 models in total, and that WDC drives accounted for a quarter of all models in the “below 1%” group.
The dubious honor of the least reliable drive of 2025 goes to the Toshiba MG08ACA16TEY 16TB, which posted a failure rate of 6.30%, the only drive to break the 6% threshold. However, this result comes with a major caveat: the drive recorded an apparent failure rate of 16.95% in Q3 2025. This spike was due to Backblaze working with Toshiba to deploy firmware updates to this model, which required many drives to be taken offline, which showed up in the data as failures. As shown below, reliability stabilized in the following quarter, and the drive has been fairly reliable historically. So, let’s take a look at the second-worst performer.
That would be the Seagate ST10000NM0086 10TB, which had a yearly failure rate of 5.66%. This time, it’s likely due to its age: it’s more than seven years old and has a relatively small number of units in operation (1,044), with every failure contributing significantly to the total rate. In other words, the drive isn’t bad, it’s just old, but still useful.
The most reliable HDD model of 2025 was also made by Western Digital
Closely followed by a Seagate model
When factoring in both the number of drives in use and their failure rates, the most reliable drive of 2025 was the WDC WUH722222ALE6L4 22TB. There are 44,577 units in operation in Backblaze’s data centers, with an annual failure rate of just 0.47%. Talk about reliability.
The WDC model is closely followed by the Seagate ST16000NM001G 16TB, which has a 0.54% failure rate across a massive sample of 34,563 units currently in operation.
HDDs were more reliable in 2025 than in the previous few years
The annual failure rate (AFR) for 2025 was just 1.36%, a notable improvement over the previous couple of years. For example, AFR stood at 1.57% in 2024 and a relatively steep 1.70% in 2023. That said, when looking at historical trends, the 2025 figure is roughly in line with the lifetime AFR of 1.30%.
What this tells us is that enterprise storage drives are extremely reliable. Sure, some models perform worse than others, and certain vendors have quite high failure rates (HGST, for example), relatively speaking, but when you look at the bigger picture, the overall level of reliability is striking.
The biggest winner of 2025, at least according to Backblaze’s data, was Western Digital. Not only was it crowned the most reliable vendor overall, but it also produced the most reliable HDD of the year. A clean sweep.
- Storage Capacity
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2 – 26TB
- Workload
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550TB/yr
Western Digital’s Red Pro NAS hard drives come in sizes from 2TB to 26TB.



