Most hard drives and SSDs keep a health log, called SMART: counts of damaged sectors, read errors, wear, temperature and hours in use. macOS gives you only a one-word summary of it. Reco’s Drive Check-up reads the log and tells you what it says in plain words, with a verdict you can act on.
It’s free and read-only. Nothing is written to the drive.
The free built-in option first
macOS can tell you whether a drive’s own overall check passes. Open Terminal, run diskutil list to find the drive’s identifier (such as disk0 for the built-in disk), then run diskutil info disk0 | grep SMART. “Verified” means the drive’s overall check passes; “Failing” means copy what matters now. Many external drives show “Not Supported”, because the connection doesn’t pass the data through.
How to run a check-up
- Open Drive Check-up from More ways Reco can help or the Tools menu.
- Choose the drive. Reco asks the drive for its health log. It takes a moment.
- Read the verdict. One of four:
- Looks healthy: the drive reports nothing wrong.
- Worth watching: early signs of wear or trouble. Keep a backup current.
- Copy it now: the drive reports damage. Copy what matters before you do anything else with it.
- Can’t tell: no health data could be read, so Reco won’t guess.
- See what the drive says. Under the verdict, each finding is one plain sentence: for example how many damaged sectors have been replaced with spares, how many sectors can’t be read right now, how much of an SSD’s rated life is used, the temperature, and how long it has been powered on.
- Open “The numbers behind it” if you want the raw values the verdict is based on.
When the verdict is Copy it now or Worth watching for an external drive, Reco offers Copy this drive first, which starts Copy first: one careful copy to a disk image before anything else reads it.
How to read the findings
- Sectors waiting to be replaced, or unreadable: files stored there may already be damaged. This is the most serious sign.
- Replaced sectors: a few can stay stable for years. A number that keeps growing is the warning sign.
- Transfer (CRC) errors: usually the cable or the enclosure, not the drive. Try another cable first.
- SSD life used: many drives keep working beyond their rated life, but keep a backup current.
Honest limits
- No data means no verdict. SD cards, USB sticks and many USB enclosures and adapters don’t pass health data to the Mac. Reco shows Can’t tell and never calls a drive healthy from silence.
- Sometimes only the one-word answer gets through. Reco says so, and judges from that alone.
- Healthy isn’t a promise. Drives can fail without warning. A check-up is a reason to act, not a reason to skip backups.
- It doesn’t repair anything. If a drive is failing, the fix is to copy what matters off it and replace it.
Questions
How do I check a drive’s SMART status on a Mac for free?
In Terminal, run diskutil info disk0 | grep SMART (use the drive’s own identifier from diskutil list). It gives a one-word answer. Reco’s Drive Check-up reads the details behind it and explains them.
Why does Drive Check-up say “Can’t tell” for my SD card or USB stick?
Many cards, USB sticks, adapters and enclosures don’t pass health data to the Mac. That says nothing about the drive either way, and Reco won’t guess.
Does a healthy result mean my drive won’t fail?
No. Drives can fail without warning. A healthy result means the drive reports nothing wrong right now, so a backup is never wasted.
Does Drive Check-up write anything to the drive?
No. It only reads the drive’s own health log.