SMARTastic

A native macOS app for understanding the health of your SSDs and hard drives. Built with SwiftUI, powered by smartmontools, and developed by Robin Bially.

Actual app screenshots, using clearly labelled synthetic demo data.

What it shows

• Internal and external drives, including Apple SSDs, NVMe drives and ATA disks.
• Clear health states: good, warning, critical or unknown. Failed SMART status, NVMe critical warnings and depleted endurance are never hidden by a green score.
• Available measurements: temperature, rated endurance, spare capacity, media/sector error counters, data read/written, power-on hours and power cycles.
• Daily write history: a native bar chart for 7, 30 or 90 days, with a today summary and selectable bars. Uses real timestamps and counter differences, independently of SMART power-on hours.
• Drive search by model or interface, with native keyboard selection and Escape to clear the focused search field.
• Refresh controls: native segments for pause/manual, every 30 seconds, every minute (default), or every five minutes. The last successful scan time stays visible.
• JSON report export with a versioned schema and measurement timestamp. Serial-number fields are omitted; review diagnostic text before sharing.
• Read diagnostics with a full-width clickable disclosure row and useful guidance when smartmontools or SMART access is unavailable. A failed scan preserves the previous snapshot and shows a warning.
• Compact layout and native circular actions, with content scrolling beneath the transparent window header.
• A sun/moon appearance switch, with system appearance by default (right-click the switch to restore it), plus English, German, French, Spanish and Simplified Chinese translations selected from your system preferences.

Daily write history

History starts when this version first scans a drive. SMART only exposes a lifetime counter; it cannot reconstruct earlier daily usage. Keep SMARTastic open with periodic refresh enabled to collect regular measurements. There is no background agent when the app is quit. ⌘W minimizes the window so measurement can continue; ⌘Q quits the app. The standard ⌘M shortcut also remains available.

The chart shows measured GB, not extrapolated full-day totals. Missing days stay empty; an observed zero is shown as a dot. Today's value and other partially observed days are incomplete. Select a bar to see its measured amount and covered hours. Hover over the chart for a floating daily detail card, including explicit missing-data messages. Click to pin a day; click it again to clear the selection. Buttons and period controls include contextual tooltips. Short intervals crossing midnight (up to 10 minutes) are split in proportion to elapsed time. Longer intervals crossing days are reported separately rather than assigned to invented daily totals. Their entire volume is reported if the interval overlaps the selected period, so it may include writes outside that period.

Up to 90 calendar days are kept locally in ~/Library/Application Support/SMARTastic/write-history.json. A hash of model and serial identifies each drive across device-path changes; raw serial numbers are not stored. Drives without a reliable serial or write counter cannot be tracked. Counter decreases establish a fresh baseline. The calendar time zone is fixed when the history is created and displayed under the chart's measurement explanation. Demo history stays in memory and never enters the real history file. The existing JSON report exports the current SMART snapshot, not this local history.

Install

Requires macOS 14 Sonoma or later and smartmontools 7 or later. The app supports Apple Silicon and Intel. Homebrew distribution uses the LocalFoundry tap.

Install the signed and Apple-notarized Universal app through Homebrew:

brew install --cask localfoundry/tap/smartastic

The cask also installs smartmontools. For a manual app download from GitHub Releases, install smartmontools separately:

brew install smartmontools

SMARTastic looks for smartctl at /opt/homebrew/bin/smartctl on Apple Silicon and /usr/local/bin/smartctl on Intel. It does not ask for administrator access, install a privileged helper, start disk self-tests, or change drive settings.

Understanding the numbers

SMART reports what a drive and its controller expose. USB adapters, RAID controllers and access permissions can prevent some or all SMART data from being read. The app still shows the available macOS drive information.

A dash means unavailable, not zero. ATA attribute meanings vary by vendor; unsupported SSD wear and traffic counters are not guessed. For NVMe, one data unit is 512,000 bytes, and TB/GB use decimal units. ATA error counts aggregate reported reallocated, pending and offline-uncorrectable counters; categories can overlap and are not a count of distinct failing sectors.

Remaining rated endurance is not a lifespan prediction. It is 100 minus the manufacturer's wear indicator, clamped at zero. SMART power-on hours can exclude low-power states. “Written per 24 SMART hours” divides lifetime written bytes by the drive-reported power-on hours and normalizes to 24 hours. It is not necessarily a calendar-day average and is not the current write speed. A measured calendar-day average would require counter differences between timestamped observations. The calendar lifespan forecast and arbitrary HDD health percentage were removed because they suggested more certainty than SMART provides. See the NVMe SMART log field definitions.

A good SMART result cannot rule out a sudden failure. Keep backups regardless of the displayed status. SMARTastic makes no network requests; reports are saved only to the destination you choose.

Build from source

Use full Xcode 26.3 or later and its command-line tools. If the selected Command Line Tools SDK lacks the SwiftUI macro plugin, select full Xcode or set DEVELOPER_DIR for the build; see release documentation.

brew install smartmontools
git clone https://github.com/RobinBially/SMARTastic.git
cd SMARTastic
swift test
./scripts/make-app.sh
open .build/app/SMARTastic.app

The script creates a release build for the current architecture and signs it ad hoc for local development. To build both architectures:

ARCHS="arm64 x86_64" ./scripts/make-app.sh

Launch a synthetic demo for screenshots (no drive reads):

open .build/app/SMARTastic.app --args --demo --light -AppleLanguages '(en)'
# Use the Appearance switch for System, Light or Dark.

Build, signing, notarization, release resumption and Homebrew maintenance are covered in docs/RELEASING.md. The review findings and actual verification scope are recorded in docs/REVIEW-1.1.0.md.

License

MIT.