What is a good annualized failure rate?

Below about 1% per year is solid for a hard drive at scale. A single low or zero figure from a small sample is not proof on its own - look at the drive count and age behind it too, which we show on each drive's page.

Is Backblaze data representative of my home NAS?

Partly. Backblaze runs enterprise drives 24/7 in a datacenter, so the AFR figures are strongest for Exos, Ultrastar and MG-class drives. Consumer NAS lines like IronWolf and WD Red Plus have little large-scale public failure data, so judge those on class, warranty and workload rating.

Does a low failure rate mean I can skip backups?

No. Every drive can fail, and AFR is a fleet average, not a guarantee for your unit. Keep a 3-2-1 backup - RAID gives you uptime, not a backup.

Most Reliable NAS Drives (2026): Lowest Failure Rate

	Drive	Capacity	Tech	Class	Interface	AFR	€/TB	Price
1	ST16000NM000J Seagate Exos X18	16 TB	CMR	Enterprise	SATA	0.22%	€27.49	€440
2	WUH722626ALE6L4 WD Ultrastar DC HC590	26 TB	CMR	Enterprise	SATA	0.40%	€41.42	€1,077
3	WUH722222ALE6L4 WD Ultrastar DC HC570	22 TB	CMR	Enterprise	SATA	0.47%	€51.11	€1,124
4	ST16000NM001G Seagate Exos X16	16 TB	CMR	Enterprise	SATA	0.54%	€31.16	€499
5	MG10ACA20TE Toshiba MG10	20 TB	CMR	Enterprise	SATA	0.59%	€43.30	€866
6	MG11ACA24TE Toshiba MG11	24 TB	CMR	Enterprise	SATA	0.68%	€42.38	€1,017
7	WUH721816ALE6Lx WD Ultrastar DC HC550	16 TB	CMR	Enterprise	SATA	0.80%	€41.25	€660
8	WUH721414ALE6L4 WD Ultrastar DC HC530	14 TB	CMR	Enterprise	SATA	0.81%	-	-
9	ST12000NM001G Seagate Exos X16	12 TB	CMR	Enterprise	SATA	0.96%	€36.77	€441
10	MG07ACA14TE Toshiba MG07	14 TB	CMR	Enterprise	SATA	1.18%	-	-

Ranked by measured failure rate (Backblaze AFR). $/TB shows once live prices are wired.

How we rank reliability

We pin Backblaze Drive Stats to the exact models currently on sale, compute the annualized failure rate from failures over drive-days, and sort lowest first. The fleet-wide average appears on each drive page so a number has context: a 0.6% AFR means little without knowing whether it rests on one failure or fifty.

Reliability is one axis. Cross-check capacity, price per TB and noise before buying - a drive with a marginally lower AFR but a far worse price per TB is rarely the better array.

Frequently asked questions

What is a good annualized failure rate?: Below about 1% per year is solid for a hard drive at scale. A single low or zero figure from a small sample is not proof on its own - look at the drive count and age behind it too, which we show on each drive's page.
Is Backblaze data representative of my home NAS?: Partly. Backblaze runs enterprise drives 24/7 in a datacenter, so the AFR figures are strongest for Exos, Ultrastar and MG-class drives. Consumer NAS lines like IronWolf and WD Red Plus have little large-scale public failure data, so judge those on class, warranty and workload rating.
Does a low failure rate mean I can skip backups?: No. Every drive can fail, and AFR is a fleet average, not a guarantee for your unit. Keep a 3-2-1 backup - RAID gives you uptime, not a backup.