SpareDisk Help

Short, plain answers to the questions the interface raises: what the numbers mean, why some items cannot be moved, and what the Trash frees. The same text is available inside the app under Help.

Sizes

Logical size

What a file would hold if it were fully downloaded and uncompressed. Finder shows this number in Get Info as the first figure.

Size on disk

The space a file actually occupies right now. Cloud files that are not downloaded, sparse disk images and cloned copies take far less than their logical size. SpareDisk shows an on-disk hint whenever a file occupies less than half its size. The View menu and Settings switch every list, map and total to sizes on disk.

Why totals differ

The volume bar counts everything on the disk. A location counts only what is inside it. System files, other users, snapshots and folders you have not added as locations make up the rest. Hard links are counted once, as du does.

Views and colors

Three views

Every location shows as a map, a sunburst or a list; the toolbar switches between them. The map draws each item as a cell in proportion to its size and folds cells too small to read into one labelled group. The sunburst shows the current level as the inner ring and what is inside each folder as the outer ring; a grey sector gathers the smaller items and opens the list. Double-click drills into a folder in either view; the breadcrumb or the center of the ring goes back up.

What the colors mean

By Folder gives the largest items at each level distinct muted hues by rank, so the map reads as shape. By Type colors every item by its kind with the same colors used for dots and bars throughout the app. By Age shades items from vivid for recent to grey for old, in five steps from under six months to over five years. The choice sits in the bar above the map and a legend appears for type and age.

File kinds

Kinds are decided by extension and by package type: Documents, Media, Archives and Installers, Developer, Applications, System and Library, and Other for anything else. My Mac and File Types total every file in the scanned locations by kind, counting nested locations once. Scans saved before totals existed contribute nothing until rescanned, and the screen says which.

Why My Mac and Finder disagree

My Mac uses sizes on disk for the volume picture and logical sizes for the file type bar, and says so under each. If the scanned folders add up to more than the disk shows as used, the excess is reported rather than hidden; cloned and sparse files are the usual cause, and a rescan refreshes stale figures.

Locations and permissions

What a location is

A folder you granted SpareDisk access to. Your home folder covers Desktop, Documents, Downloads and Library in one step. Applications and external drives are separate locations. Several folders can be added at once and scan one after another.

Why macOS asks

macOS confirms once before an app reads a protected folder such as Desktop or Downloads. SpareDisk never asks for Full Disk Access and cannot read outside the folders you add.

Forgetting a location

Forget Location in the sidebar removes the saved permission and the saved scans for that folder. Nothing on disk changes.

Review and the Trash

Review first

Add to Review stages items in a queue. Nothing moves until you confirm. Move to Trash in the inspector does the same for one item, or for every selected item, with a confirmation.

Checked again

Before an item moves, SpareDisk checks that it is still the same file: same identity, size and date, still inside the location. Anything that changed is skipped and listed with the reason.

What the Trash frees

Moving to the Trash frees nothing by itself. Space returns when you empty the Trash in Finder. Cloned files and files with several hard links may free less than their size.

Items SpareDisk cannot move

Apps and files owned by the system or another user need an administrator password, which only Finder can ask for. Cloud files that are not downloaded are managed in Finder as well. SpareDisk says so on the item and offers Finder.

Duplicates

How they are found

Among the largest files of each scanned location, files of the same size are sampled at the start, middle and end, hashed with SHA-256, then compared byte by byte. Only identical contents are grouped. Progress is shown by bytes read.

Keeping one copy

Each group keeps one copy. Stage the Rest for Review stages the others; the kept copy is never moved by group actions, and cleanup refuses the last copy of any group.

Identical is not the same

Two identical files can mean different things to different apps. Check where each copy lives before removing it.

Related data for apps

What Find looks for

Containers, group containers, caches, preferences, saved state, logs and Application Support that match the app's bundle identifier under your Library, plus vendor folders such as Google/Chrome. Matches by name only are marked as weaker evidence. Each item is scanned for its real size.

What it does not do

SpareDisk does not uninstall apps or stop background helpers. Items go through the same review and Trash flow as everything else, and nothing is preselected.

Uninstall and leftovers

Uninstalling an app

Select an app and choose Uninstall from the inspector or the context menu. SpareDisk reads the app's bundle identifier from its Info.plist and looks under your Library for containers, group containers, caches, preferences, saved state, web storage, logs and scripts with that identifier. Those are checked. Folders that only share the app's name or vendor are shown as possible matches and start unchecked. Add to Review stages what you ticked; nothing moves until you confirm in Review Cleanup.

Why Uninstall is sometimes unavailable

It is disabled while the app is running, when the app cannot be moved (for example one owned by the system, which needs an administrator password only Finder can ask for), and when your home folder has not been added, because the app's data lives under its Library.

What Leftovers lists

Entries in the Library folders that are named by a bundle identifier, such as com.example.App, for which no installed application claims the identifier or any of its parents. Helpers like com.example.App.Helper belong to com.example.App. A copy of an app sitting in the Trash or in a build folder does not count as installed. Apple's own identifiers are never listed.

Deciding what to move

Each group names the app and shows every item with its kind, place and date. Move to Trash on a group asks first and checks each item again before moving it. Some identifiers belong to command-line tools or to apps kept outside the usual folders, so read the name before moving anything.

What stays out of reach

Login items, launch agents and daemons in /Library, kernel and system extensions, and anything under /private cannot be read or removed by a sandboxed app. After removing an app, check System Settings, General, Login Items for anything it registered.

Comparing scans

SpareDisk keeps the previous completed scan of each location. The location's bar shows the change since then, and clicking it lists the top-level folders and files that grew, shrank, were added or were removed. Unreadable folders are reported as unreadable, not as removed.

Keyboard

• ⌘O add a location. ⌘R rescan the current location. ⌘I show or hide the inspector.
• Space Quick Look. Return open or expand a folder. Arrow keys move between map cells.
• ⌘⇧R add the selection to Review. ⌘⌫ move the selection to the Trash after confirmation.
• ⌘[ and ⌘] go back and forward. ⌘? open Help.

Privacy

Everything stays on this Mac

Scanning reads names, sizes and dates. Duplicate comparison reads file contents to hash them. Nothing is uploaded and there is no account.

What is stored

The last two scans per location and your saved folder permissions live in the app's own container. Forget Location removes them. See the privacy policy.