How to Check SSD Health on Mac

If your Mac starts freezing during file copies, an external SSD disconnects, or a drive suddenly turns read-only, check the storage before you keep troubleshooting around it. To check SSD health on a Mac, open Disk Utility, choose View > Show All Devices, select the physical drive, click Info, and read its S.M.A.R.T. status.

Treat Verified as “no current hardware failure warning is being reported,” not as a promise that the drive cannot fail. If you see a failure or fatal hardware warning, protect the data first: back up what you can and arrange service or replacement.

Quick Answer: Check Mac SSD Health in Disk Utility

1. Open Applications > Utilities > Disk Utility.
2. Choose View > Show All Devices.
3. Select the top-level physical storage device, not only an indented APFS volume.
4. Click Info in the toolbar.
5. Find S.M.A.R.T. status when the selected device reports it.

Apple describes S.M.A.R.T. as the disk's general working condition. The result is useful, but narrow: it reports the hardware telemetry macOS can read from that device. It does not check every file, predict every sudden controller failure, or measure transfer speed.

S.M.A.R.T., First Aid, and SSD Speed Answer Different Questions

The three checks are easy to mix up because they all live near storage tools.

Apple says Disk Utility First Aid checks formatting and directory structure. A drive can pass S.M.A.R.T. and still have a file-system problem. It can also benchmark slowly because of a cable, hub, background transfer, heat, or workload without reporting a hardware failure.

Tip: Start with the symptom. A health warning calls for a backup. A damaged volume calls for First Aid. A repeatable throughput problem calls for a controlled Mac disk benchmark.

Step 1: Check S.M.A.R.T. Status in Disk Utility

Disk Utility is the safest built-in starting point because this check is read-only and takes less than a minute.

1. Open Disk Utility from Applications > Utilities.
2. Choose View > Show All Devices. This exposes physical devices above their containers and volumes.
3. Select the physical drive at the top of the relevant group.
4. Click the Info button in the toolbar.
5. Look for S.M.A.R.T. status in the device information.

The image above comes from Apple's current Disk Utility guide and is only an orientation reference for the Info control. It shows an APFS container, not the physical-device selection or a S.M.A.R.T. result. Your sidebar, device name, capacity, and APFS layout will differ.

Apple notes that the details depend on the selected item, so select the physical device when possible. A volume such as “Macintosh HD” is a logical file-system layer; the device above it is the storage hardware whose S.M.A.R.T. state you want.

How to read the result

• Verified: macOS is not receiving a recognized S.M.A.R.T. failure status from that device right now. Keep backups anyway.
• Failing or fatal hardware error: back up important data immediately. Apple's guidance is direct: Disk Utility and other software-repair tools cannot fix an irreparable hardware problem.
• Not Supported, absent, or unavailable: macOS did not give you a usable health verdict for that selection and connection path. Do not translate missing telemetry into “healthy.”

Tip: If the drive is clicking, disappearing, corrupting files, or repeatedly turning read-only, trust the symptoms enough to make a backup even when the displayed S.M.A.R.T. state is Verified.

I read the one-word status as a triage signal: a warning changes what I do immediately, while a green result only tells me to keep investigating the symptom in the right layer.

Step 2: Check SSD Health in Terminal

Terminal exposes the same high-level status without navigating Disk Utility. It is useful for a quick check or a support note, but it does not magically reveal telemetry the hardware path does not provide.

Open Terminal and run:

diskutil info / | grep 'SMART Status'

The / asks diskutil about the current startup volume. On the working Mac used to verify this article, macOS 27.0 prerelease returned SMART Status: Verified on 2026-08-17. That observation confirms the command and label, not the health of anyone else's Mac.

For Apple NVMe storage, this built-in command can show a little more context:

system_profiler SPNVMeDataType | grep -E 'S.M.A.R.T.|TRIM Support|Capacity'

system_profiler may list capacity, TRIM support, and the overall S.M.A.R.T. state. TRIM and S.M.A.R.T. are different: TRIM is a storage-management feature, while S.M.A.R.T. reports health information.

Check a specific external physical disk

First list only attached external physical disks:

diskutil list external physical

Find the identifier for the intended device, such as disk4, then substitute the identifier you actually saw:

diskutil info disk4 | grep 'SMART Status'

Never copy a sample disk number blindly. Disk identifiers can change after drives are connected, disconnected, or restarted.

If the command prints no S.M.A.R.T. line, the result is unknown through this method. The drive, enclosure bridge, cable path, and macOS all have to expose compatible telemetry. Try a direct connection and current manufacturer guidance for that exact drive or enclosure, but do not install a random “health” utility simply because it promises a percentage.

Step 3: Read the Drive Health Report in Sensei

The built-in macOS result is intentionally terse. Sensei is useful when you want the supported NVMe health fields explained in one dedicated report instead of a one-word status.

As of August 2026, the current Sensei release is 2.1.2 and requires macOS 14 or later. To open the report:

1. Open Sensei.
2. Select Storage in the sidebar.
3. Choose the drive you want to inspect.
4. Select Health from the available storage features.
5. Review the overall condition and the fields the drive reports.

The current Drive Health report can surface values such as:

• Critical Warning: whether the NVMe controller is reporting a critical condition.
• Available Spare: the normalized percentage of remaining spare capacity.
• Percentage Used: the manufacturer's estimate of how much NVM subsystem life has been used.
• Temperature: the storage controller's reported temperature.
• Data Units Read and Written: lifetime I/O counters reported by the drive.

Those names come from the NVMe health model, but the values remain drive-reported estimates. The NVM Express specification defines Percentage Used as manufacturer-predicted life consumption and Available Spare as remaining normalized spare capacity. Neither number is a countdown clock to an exact failure date.

Why an External SSD May Show No Health Data

External storage is where a careful answer matters most. Apple says Disk Utility information depends on the item selected and can include S.M.A.R.T. status; it does not promise that every external device exposes it.

When the field is absent or unsupported:

1. Confirm you selected the top-level physical external device.
2. Connect the drive directly to a compatible Mac port when practical.
3. Try a known-good cable and check that the enclosure has stable power.
4. Re-run diskutil info for the correct physical identifier.
5. Check the drive or enclosure maker's current support documentation for a compatible diagnostic path.

The honest result may still be “health telemetry unavailable.” In that case, watch the evidence you do have: disconnects, I/O errors, corrupted files, unusual sounds from a hard drive, a read-only state, and failed copies. Keep at least one other copy of irreplaceable data.

Tip: A successful First Aid run on an external volume does not fill this gap. It means Disk Utility checked or repaired the file-system structures it can inspect—not that the enclosure exposed hardware-health data.

What to Do When SSD Health Looks Bad

Work in this order:

1. Stop nonessential writes. Do not run repeated benchmarks or cleanup passes on a drive that is already warning or disconnecting.
2. Copy the irreplaceable files first. Prioritize documents, photos, keys, and current projects before a large all-or-nothing transfer.
3. Use another destination. A second physical disk or a trusted cloud copy is safer than moving files elsewhere on the same device.
4. Record the evidence. Save the exact warning, device name, connection path, and time.
5. Arrange service or replacement. A failing internal Apple SSD requires Mac service; a failing external device should be removed from primary or backup duty.

If the hardware status is Verified but files will not copy or a volume will not mount, use First Aid next. If reliability is stable but performance feels slow, run a controlled speed test. Change the question only after you have protected the data.

How Often Should You Check SSD Health?

I would not turn this into a daily ritual. Check when:

• a drive disconnects or becomes read-only;
• files fail to copy or arrive corrupted;
• Disk Utility or macOS shows a storage warning;
• an older drive takes on primary or backup duty;
• you are establishing a maintenance baseline before an important project.

A current backup matters more than a green dashboard. S.M.A.R.T. is an early-warning channel, not insurance against every failure mode.

Back Up First, Then Diagnose the Right Layer

The best SSD health check is the one you interpret correctly. Disk Utility gives you the fast S.M.A.R.T. verdict. Terminal makes that result easy to record. Sensei adds readable NVMe wear, spare-capacity, temperature, and lifetime-I/O context when the drive reports those fields.

None of them replaces a backup. When the storage itself may be unreliable, protect the files first—then decide whether you need hardware service, First Aid, or a speed test.

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Related guides:

• Mac Disk Benchmark: How to Test Your SSD Speed
• How to Check Mac Storage
• How to Free Up Disk Space on Mac