Answers, without the hedging.

Why does Strata need Full Disk Access?

Because macOS hides Mail, Messages, Safari and other apps' data from any app that has not been granted it.

Without the permission Strata still scans and still works: those folders are simply invisible, and your totals come out short by whatever is in them. The app tells you when that has happened rather than quietly reporting a wrong number.

Granting it takes three steps in System Settings and requires relaunching the app, because macOS only applies the change at launch. Nothing is uploaded either way: Strata has no network code beyond the update check.

Does Strata delete anything permanently?

No. Everything goes to the Trash.

That means Finder can put it back even if you never open Strata again, and it means a mistake costs you a click rather than a backup restore. Strata also has its own one-click undo for the last batch.

Some disks have no Trash: certain network shares and external volumes. There, removal fails and tells you why. It never falls back to a permanent delete to get the job done.

Can it delete something important by mistake?

There is a list of things it refuses to touch, checked twice: once when the confirmation is built and again immediately before anything moves.

• System folders: /System, /bin, /usr (except /usr/local), /Library/Apple
• Your keychain
• The standard folders in your home directory: their contents can go, the folders stay
• Anything in iCloud Drive, because deleting it here removes it from every device you own
• Volume roots, and Strata's own application bundle

Skipped items appear in the confirmation with the reason, rather than vanishing from the list without explanation.

How complete is the app uninstaller?

It searches eighteen Library locations and rates every match, and it deliberately leaves some leftovers behind.

Matches are graded from certain to possible. Anything below "very likely" arrives unticked, because a missed leftover costs a few megabytes and a wrong one costs data.

The deliberate gap: it will not remove a folder shared by several apps from the same vendor. Taking Application Support/Google while uninstalling Chrome would take Drive's data with it. That trade means Chrome's own subfolder is not found either. Given the alternative, it is the right way round.

Does it need administrator rights?

No, and it never asks.

A handful of leftovers live in folders owned by the system: launch daemons, helper tools. Strata lists them so you know they exist, with a button to reveal them in Finder, and does not touch them. No helper daemon is installed and no password is requested at any point.

Is this a subscription?

No. Every tier is a one-time purchase and does not expire.

Bug fixes, security fixes and macOS compatibility updates are free forever at every tier: you never pay to keep a version you already own working. New features arrive as a higher tier you can choose to buy, for the difference in price.

What data does Strata collect?

None. No account, no telemetry, no analytics, no crash reporting.

The only network request is an optional check for updates, which you can turn off in Settings. Licence keys are verified on your Mac using cryptography rather than by asking a server for permission, so activation works offline, and if this company disappeared your copy would carry on working.

The full detail is on the privacy page, which is short for the same reason.

What are the system requirements?

macOS 13 Ventura or later, on Apple silicon or Intel.

The download is a universal binary of about 14 MB, signed with a Developer ID and notarized by Apple. The notarization ticket travels inside the download, so it opens on the first try even on a Mac that is offline.

How long does a scan take?

Under a minute for a full boot volume on most Macs, and a few seconds for a folder.

Strata reads directories in batches through a single kernel call rather than asking about files one at a time, which is most of the difference. Results stream into the map as they arrive, so you can start reading it before the scan finishes.

Why is it not on the Mac App Store?

Because App Store apps are sandboxed, and a sandboxed app cannot read ~/Library: which is the entire product.

Every disk analyzer worth using is distributed directly for the same reason. Strata is signed with a Developer ID and notarized by Apple, which is the same review for malware that App Store apps get; what it does not get is the sandbox that would make it useless.