Side by side
HDD Health Monitor vs Prefail
Both stand on disk health monitoring software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan Windows
HDD Health Monitor brings drive health indicators, alerts, and retained history into a standalone Windows utility. Its ability to read S.M.A.R.T. data depends on drive and controller support, and it requires administrator privileges.
Visit HDD Health Monitor
Free plan APILinux
Choose Prefail if you need S.M.A.R.T.-based disk monitoring, alerts, and fleet reporting for Linux servers. Look elsewhere if you need protection against sudden electrical or controller failures; Prefail explicitly says monitoring does not replace backups.
Visit PrefailThe facts
| HDD Health Monitor | Prefail | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | Windows | API, Linux |
| Lowest paid plan | Free or on request | PRO: $9 a month |
| Plans published | 1 | 5 |
| Maker | Not published | Not published |
| Website | hddmonitor.github.io | prefail.io |
| On disk health monitoring software | #13 of 28 | #16 of 28 |
HDD Health Monitor: what it does well
- Monitors multiple physical drives automatically.
- Records selected health data every five seconds while running.
- Provides several drive-health and failure alerts.
- Runs without an installer or dependencies.
- Free, MIT-licensed, and requires no registration.
What to know first
- Administrator privileges are needed to read S.M.A.R.T. data.
- USB bridge support can prevent S.M.A.R.T. access.
- S.M.A.R.T. data usually cannot be read from unofficial flash drives, memory cards, or eMMC products.
- Some Windows antivirus products may incorrectly flag it as malware.
Prefail: what it does well
- Scores each disk using 25+ S.M.A.R.T. attributes.
- Shows seven-day score deltas and stable or rising signals.
- Supports individual disk health behind supported RAID controllers.
- Provides Telegram alerts, dashboard, and email fallback.
- Sends a weekly PDF fleet report.
What to know first
- The free plan covers up to 2 servers.
- S.M.A.R.T. cannot warn about some sudden failures.
- Prefail says it is not a substitute for backups.
Alternatives to HDD Health Monitor Alternatives to Prefail The whole list