Mac storage basics

Open System Settings → General → Storage. You can also select Macintosh HD in Finder and press Command-I, turn on Finder's status bar, or open Disk Utility.

From macOS Ventura onwards it lives in System Settings → General → Storage. About This Mac's More Info button takes you to the General settings, where Storage is listed.

Finder and Storage settings count purgeable space (snapshots, cached cloud files) as available; Disk Utility's Free figure and df count only space that is free right now.

A small part of the drive is reserved for macOS Recovery and other hidden system areas, so Macintosh HD reports slightly less than the advertised size. It's normal and doesn't grow.

Keep roughly 10–15% of the drive free. macOS needs room for virtual memory, snapshots and especially system updates; running near full causes slowdowns and failed updates.

Store in iCloud keeps Desktop and Documents online-only when space is low, Optimise Storage removes watched Apple TV videos, and Empty Trash Automatically deletes items left in the Trash over 30 days.

In Finder's List view, open View Options (Command-J) and tick Calculate all sizes, then sort by Size. For one folder, select it and press Command-I.

Run df -h to see each volume's free space, and du -sh ~/* | sort -h to rank the items in your home folder by size. Some folders need Full Disk Access for Terminal.

Macintosh HD is the sealed, read-only macOS system; Macintosh HD – Data holds your apps and files. They share the same space, and the Data volume must never be deleted.

Not on Apple silicon Macs — internal storage can't be upgraded by the owner. Extra room comes from an external SSD or cloud storage.

Usually photos and video, large apps, System Data (caches, snapshots, logs), iPhone backups, forgotten downloads, mail and chat attachments, and developer caches.

Storage settings is a good overview, but it can't move data to an external drive or explain sudden space loss. Storage Studio uses the same macOS features and adds those parts.

It depends on what you keep locally: light, cloud-based use fits base storage; local photo libraries, video, development or games need more or an external SSD. Internal storage can't be upgraded later.

It measures every category, which can take minutes after updates, on a full disk or during Spotlight indexing. Wait, then restart; rebuilding Spotlight's index can help.

Auto-empty the Trash after 30 days, clear Downloads monthly, review screenshots, keep only your latest iPhone backup, archive finished projects and watch free space.

Select the items and press Option-Command-I; the Finder Inspector shows their combined size. Command-I opens a separate window per item.

In icon view, press Command-J and tick Show item info to see file sizes and folder item counts under icons.

Finder calculates and caches folder sizes in the background, so they lag after changes, and unreadable or online-only items skew them. Use Command-I to recalculate.

System Data is macOS's catch-all label for caches, logs, local snapshots, virtual memory, app support files and anything it can't classify. Older versions called it Other.

Usually local snapshots, app and browser caches, developer data, swap files, logs or device backups. Some shrinks on its own after a restart or within a day.

Restart, release local snapshots, clear rebuildable app caches, remove old device backups and clean developer data. Don't delete files in system folders by hand.

Restarting clears swap (virtual memory) files, the system's temporary folder and some rebuildable caches. It never touches your own files.

It covers most loose files in your home folder — Downloads, Desktop, disk images, archives and videos outside Photos — not only the Documents folder.

It's the sealed, read-only macOS system and can't be trimmed. Shrink System Data, your apps and your own files instead.

It's data left by Xcode and its tools — build products, caches and indexes — which are rebuilt on the next build and can usually be deleted.

iPhone and iPad backups and update files stored on your Mac. You can review and delete old ones from the category's info button.

Space used by other volumes sharing your startup disk's container — mostly macOS's hidden Preboot, Recovery and swap volumes, plus any volume you added yourself.

Files in other user accounts plus the Macintosh HD › Users › Shared folder. Clean up from inside those accounts, or remove accounts you no longer need in Users & Groups.

It's GarageBand and Logic Pro's downloaded instruments, loops and samples. Remove it from the category's info button in Storage settings if you don't make music.

Space macOS is using but will free automatically when needed — mostly local snapshots, downloaded iCloud copies and some caches. Finder counts it as available.

Release local snapshots (tmutil or a snapshot tool), make iCloud files online-only with Remove Download, and restart. macOS otherwise frees it only when an app asks.

Point-in-time records of your startup disk kept on the Mac by Time Machine and before updates. They hold the space of changed or deleted files and usually expire within a day.

A local snapshot is usually still holding the deleted files' space; it returns when the snapshot expires (about a day) or is released. Also check the Trash and Recently Deleted.

List them with tmutil listlocalsnapshots / and delete one with tmutil deletelocalsnapshots plus its date, or use Disk Utility's Show APFS Snapshots. Update snapshots may be protected.

No. They sit on the same drive as your files, so they don't protect against drive failure, theft or erasing. Keep a separate backup.

Time Machine keeps creating them about hourly while it's on, and macOS makes one before updates. They expire on their own; there's no supported way to switch them off with Time Machine on.

Not your documents. It frees purgeable items — snapshots, caches and local copies of iCloud files that stay in the cloud — which then download again when opened.

A snapshot macOS takes when installing an update so it can finish or roll back safely. It's managed by macOS and often required; leave it alone.

Mostly in ~/Library/Caches (Finder: hold Option, choose Go → Library → Caches). Some apps use Application Support or Containers instead, and there's a shared /Library/Caches.

Mostly yes — app caches are rebuildable. Quit the app first, delete only that app's cache contents, and expect a slower first launch. Leave system caches alone.

Hold Option and choose Go → Library in Finder, or use Go → Go to Folder and type ~/Library. Command-J in your home folder can keep it visible.

Press Shift-Command-. (period) in a Finder window to show or hide hidden files. They appear dimmed; avoid deleting ones you don't recognise.

Use Develop → Empty Caches (after enabling developer features in Safari's Advanced settings) to clear only the cache, or Privacy → Manage Website Data to remove site data.

In Chrome go to Settings → Privacy and security → Delete browsing data, choose Cached images and files, and leave cookies unticked to stay signed in.

In ~/Library/Logs (including DiagnosticReports) and /Library/Logs. Old app logs and crash reports are safe to delete; leave system logs to macOS, which trims them itself.

In hidden per-user areas under /private/var/folders and in /tmp. The temporary area clears on restart and macOS empties the cache area when space is tight.

It checks the startup disk and clears some system caches, which can fix glitches, but frees little space. On Apple silicon, hold power, select the disk, then hold Shift.

Use the app's own Storage settings: clear its cache, and turn off downloads you no longer need offline. Some apps let you choose another location for offline files.

Use each app's own Clear cache option, and move or delete old local recordings (Zoom keeps them in the folder set in its Recording settings). Don't delete whole app folders.

A cache of file previews and icons for Finder and Quick Look. It's safe to reset with qlmanage -r cache in Terminal; thumbnails rebuild as you browse.

Not strictly — macOS maintains caches and logs itself. A tool helps to find what's using space, clear oversized caches safely, or offload data to an external drive.

Open Premiere Pro's Settings → Media Cache to delete unused cache files, move the cache to another drive, or have old cache files removed automatically.

Mostly the Previews.lrdata file. Discard 1:1 previews from Library → Previews, set them to auto-discard in Catalog Settings, and limit the Camera Raw cache.

In Photoshop → Settings → Scratch Disks, choose a fast external drive instead of the startup disk and restart Photoshop. Scratch files are removed when it quits.

Use Playback → Delete Render Cache, remove unneeded optimised media, and set the cache location (Working Folders in Project Settings) to a fast external drive.

In Firefox Settings → Privacy & Security → Cookies and Site Data, click Clear Data and tick only Cached Web Content to keep sign-ins.

They hold sandboxed apps' private data — caches, settings and often the only copy of documents. Don't delete them wholesale; clean up via each app or for uninstalled apps.

In Finder press Command-F, choose This Mac, set the criterion to File Size is greater than (for example 1 GB). Storage settings' Documents info button also lists large files.

Installers and .dmg files, unpacked archives, old Install macOS apps, old device backups, uploaded screen recordings and rebuildable caches — after checking you don't need them.

Yes — once the app is in Applications and the disk image is ejected, the .dmg isn't needed. The same applies to used .pkg installers and unpacked .zip files.

Sort Downloads by Size, then by Date Added; delete used installers, disk images and archives, and move anything worth keeping to an external drive or the cloud.

Tick Remove items from the Trash after 30 days in Finder → Settings → Advanced (or Empty Trash Automatically in Storage settings).

Yes — the space is only freed when you empty the Trash. Files trashed from an external drive free space on that drive when you empty the Trash with it connected.

Not from the Trash — emptying is permanent. Restore from Time Machine (including recent local snapshots) or iCloud.com's recently deleted files. Storage Studio's removals sit in its Recycle Vault.

Usually a file is still in use, locked, or lacks permission. Quit apps or restart, untick Locked in Get Info, hold Option while emptying, and run First Aid if it persists.

They go to the Desktop by default. Press Shift-Command-5, choose Options, and pick another location such as a folder on an external drive.

In Finder press Command-F, choose This Mac and search by Last opened date (optionally with File Size). Rarely-opened files worth keeping are good to move to an external drive.

APFS clones a file copied within the same drive, so both share the same data until one changes. Deleting one of a pair of clones frees little space.

Safari: Settings → General → File download location. Chrome: Settings → Downloads → Location. Firefox: Settings → General → Downloads. Choose a folder on the drive.

Many Mac items — apps, Photos and iMovie libraries, Final Cut libraries — are packages: folders shown as one file. Manage them through their app or move them whole.

Size is the content total; on disk is the space actually used. They differ because of block allocation, compression, sparse files and online-only cloud files.

Different block sizes, APFS clones and compression that don't carry over, online-only files being downloaded, or sparse files expanding. Check the file counts match.

For documents and text, often yes; for photos, video, music and apps, which are already compressed, barely at all. Right-click and choose Compress.

.DS_Store files save Finder view settings; ._ files store Mac-specific attributes on Windows-format drives. Both are tiny; deleting ._ files can drop things like Finder tags.

Choose File → New Smart Folder, add a File Size is greater than criterion, then Save and add it to the sidebar. It updates itself from Spotlight's index.

They're unfinished Safari (.download) and Chrome (.crdownload) downloads. If nothing is downloading, delete them; Safari can sometimes resume one by double-clicking.

Choose File → Reduce File Size in Keynote, Pages or Numbers. It downsamples big images and movies and removes unused media, showing the saving first.

Open it in Preview, choose File → Export and set Quartz Filter to Reduce File Size, saving as a new file. Check image quality, as it can soften pictures.

In Finder press Command-F, choose This Mac and set Kind (Movie, Image, Archive), or search a file extension by name. Sort the results by Size.

To the Downloads folder (photos and videos may open in Photos instead). Large AirDropped videos often make Downloads grow quickly.

Usually yes — they're disk images, often OS installers, and aren't needed once installed. Keep or archive one only if you'll reinstall, and check no virtual machine still uses it.

Video apps keep their libraries there — iMovie, Final Cut Pro, the TV app's media — plus saved recordings and exports. Find the biggest item and manage it in its own app.

Apps often save recordings, game saves, projects and exports there. Sort Documents by size with Calculate all sizes on, and handle app folders through their apps.

By default it's the Photos Library package in your Pictures folder. Check its size with Command-I, and never edit its contents by hand.

Deleted photos stay in Photos' Recently Deleted album for up to 30 days. Open that album and choose Delete All to free the space.

It's the one Photos library used for iCloud Photos and sharing with other apps. Set it in Photos → Settings → General with Use as System Photo Library.

Yes — hold Option while opening Photos and choose Create New. Only one library is open at a time and only the System Photo Library syncs with iCloud.

Song files live in the Music Media folder set in Music → Settings → Files. Change that location, then use File → Library → Organise Library → Consolidate files to copy them over.

In the TV app's Downloaded section, right-click an item and remove the download; purchases stay in your library. Optimise Storage in Storage settings removes watched ones automatically.

Choose File → Delete Generated Library Files to remove render, optimised and proxy media, which Final Cut can recreate. Finished libraries can be kept on an external drive and opened from there.

Yes. In Logic Pro choose Sound Library → Relocate Sound Library and pick a folder on the external drive; keep the drive connected when you use those sounds.

Editing multiplies footage into imported copies, render and proxy files, caches and multiple exports. Work from an external SSD and clear generated files from finished projects.

Generally yes — HEIC and HEVC usually give similar quality in smaller files than JPEG and H.264. Converting HEIC to JPEG typically makes files bigger.

Right-click the video in Finder and choose Encode Selected Video Files, or use QuickTime's File → Export As at a lower resolution. Keep the original until you've checked it.

It's the iMovie Library package in your Movies folder and holds copies of everything you've imported plus render files. Delete old projects and events from inside iMovie.

In Podcasts, remove downloads from Library → Downloaded and turn on automatic removal of played episodes; in Books, right-click a title and choose Remove Download.

In Music, right-click downloaded songs, albums or playlists and choose Remove Download; they stay in your library to stream. Turn off Automatic Downloads to stop new ones.

Open Media Types → Videos in Photos, or make a Smart Album filtering for movies; long and 4K videos are usually largest. Empty Recently Deleted afterwards.

It deletes every photo, video, album and edit in it unless they exist elsewhere. Even with iCloud Photos, unsynced items would be lost — optimise, move or archive instead.

Yes — each one is a still image plus a short video, so it's larger than a still. Turn Live off in the iPhone Camera for future photos.

It also stores edited versions alongside originals, thumbnails and previews, Live Photo video parts, analysis data and shared-album caches. Don't remove them by hand.

They store much more image data for editing, so they're many times larger than HEIC/JPEG or HEVC. Use them only when you'll edit, and archive originals afterwards.

It can help on a tight disk: turn off background rendering in Final Cut's Playback settings so render files are made only when you ask, at the cost of smoother playback.

Yes — untick Copy items to the Photos library in Photos → Settings → General. Referenced files aren't uploaded to iCloud Photos and break if moved or their drive is missing.

Music → Settings → Files has Copy files to Music Media folder when adding to library ticked, so songs are copied and originals remain. Untick it or delete the originals.

Small sidecar files recording edits made on an iPhone or iPad. They're tiny; deleting one keeps the photo but loses the saved edit information.

They're the video halves of Live Photos, imported as a still plus a short .MOV with the same name. Delete the .MOV files if you only want stills.

Usually the Photos Library inside it, which holds your whole collection. Manage it in the Photos app — delete and empty Recently Deleted, or move the library — never by editing it in Finder.

Only if iCloud Photos is off. With it on, deletions sync to every device — use Optimise Mac Storage instead to keep the Mac's copies small.

Use Import All New Items when importing, and decline duplicates when Photos asks. For ones already in the library, use Photos' Duplicates album under Utilities.

Mail stores local copies of messages and attachments, plus opened attachments in Mail Downloads. Delete big old messages, erase deleted items, and limit attachment downloads.

In Mail → Settings → Accounts → Account Information, set Download Attachments to Recent or None for IMAP accounts. Attachments then download only when you open them.

In a Mail Downloads folder inside Mail's container in your Library. The copies are only for viewing, so you can clear them with Mail quit; attachments stay in the emails.

Set Keep messages to 30 days or 1 year in Messages settings, delete large attachments from the Messages section of Storage settings, or use Messages in iCloud.

Use each app's own storage settings: Telegram can clear its cache and limit how long media is kept; WhatsApp lets you review and delete large media and stop auto-downloads.

Select a mailbox and choose View → Sort By → Size (descending). Delete what you don't need, then use Mailbox → Erase Deleted Items.

It re-reads the selected mailbox and rebuilds its index to fix missing or garbled messages. It isn't a cleanup tool and may re-download mail.

Gmail exposes labels, including All Mail, as IMAP folders, so Mail may store messages more than once. Hide labels like All Mail from IMAP in Gmail settings and limit attachments.

In your Library under Messages → Attachments. Don't delete there directly; remove attachments inside Messages or from the Messages section of Storage settings.

In Notes choose View → Show Attachments Browser, then use Show in Note to find and delete big attachments. Empty Recently Deleted afterwards.

There's no built-in setting, and moving Mail's folder by hand is risky. Export old mailboxes to the drive with Mailbox → Export Mailbox, then remove them from the account.

Select the messages and choose Message → Remove Attachments. On server-synced accounts the attachments may be removed from the server too, so save what you need first.

Choose Mailbox → Erase Deleted Items and Mailbox → Erase Junk Mail. Mail's account settings can erase them automatically after a set time.

Yes — it removes Mail's local copy. Server-based accounts keep their mail online; export local-only mailboxes first because they may be the only copy.

In your Library under Application Support → MobileSync → Backup. Manage them in Finder: select the device, then General → Manage Backups.

Use Finder's Manage Backups (select a connected device, General tab) or the iOS Files info button in Storage settings, and delete backups you no longer need.

Finder can't change the backup location, but the backup folder can be moved to an external drive with a link left in its place; Storage Studio does this from What's Using Space. The drive must be connected when you back up.

iCloud backups are automatic and use iCloud storage; Finder backups use your Mac's disk and can be encrypted. Many people use iCloud and keep one occasional local backup.

They're .ipsw software files your Mac downloaded to update or restore a device. They're safe to delete; Finder downloads a fresh copy if needed.

Tick Encrypt local backup in Finder. It adds saved passwords, Health and other sensitive data without making the backup much bigger — but you need the password to restore.

Open Image Capture, select the connected iPhone, set Import To a folder on the external drive and import. Files arrive as ordinary photos, not in the Photos library.

Select the iPhone in Finder and untick Automatically sync when this iPhone is connected on the General tab, then Apply. Back up manually with Back Up Now when you want.

Yes — connect once, tick Show this iPhone when on Wi-Fi in Finder and Apply. On the same network you can then use Back Up Now without a cable, though it's slower.

It includes app data, messages and attachments and, if iCloud Photos is off, your photos and videos. With iCloud Photos on, photos aren't included.

A backup you've marked in Finder's Manage Backups so the next backup won't replace it — handy before updates. Each is a full copy, so delete old ones.

Without iCloud Photos, connect the phone and import with Photos or Image Capture, ticking the option to delete after import. With iCloud Photos on, don't — deletions sync everywhere.

Quit Xcode, then clear DerivedData, old Archives you don't need, old iOS DeviceSupport versions and unused simulators/runtimes, all under ~/Library/Developer.

Yes — it's rebuildable build output and indexes. Quit Xcode and delete its contents; the next build takes longer while Xcode recreates it.

Run xcrun simctl delete unavailable to remove stale simulator devices, and remove unused runtimes in Xcode's settings under Platforms (Components in older versions).

Docker keeps images, containers, volumes and build cache in one virtual disk. Use docker system df, then docker system prune (carefully with -a and --volumes) and docker builder prune.

Run npm cache clean --force, yarn cache clean, pnpm store prune or pip cache purge. They only slow the next install while packages re-download.

Use find . -name node_modules -type d -prune (with du -sh to size them) and delete ones in inactive projects; npm install recreates them from the lock file.

Run brew cleanup to remove old versions and downloads, brew autoremove for unneeded dependencies, and uninstall tools you no longer use.

Delete unused emulators in Device Manager, remove old platforms and system images in SDK Manager, and clear ~/.gradle/caches if needed (dependencies re-download).

Run pod cache clean --all for CocoaPods; for Swift packages use Xcode's File → Packages → Reset Package Caches and clear DerivedData. Both re-download on next build.

Use cargo clean for Rust target folders, go clean -cache and -modcache for Go, conda clean --all for Conda, and delete old .venv folders. All are regenerated later.

Remove unused extensions and clear editor caches with the editor quit; in JetBrains use Invalidate Caches and remove old IDE versions' data.

Yes — keep projects on a fast external SSD and point tools like Xcode's DerivedData location at it. Use APFS, and expect builds to stop if the drive disconnects.

Ollama keeps models in a hidden .ollama folder (ollama list, then ollama rm); LM Studio and similar apps show their models folder in settings and can move it to another drive.

A VM image contains a whole operating system, and snapshots add copies of changes. Delete unneeded snapshots, use the app's reclaim/compact option, or keep VMs on an external SSD.

Yes — extra Xcode copies are ordinary apps you can delete (check xcode-select -p first). If you only need compilers and git, install just the Command Line Tools with xcode-select --install.

Run git gc, prune stale branches, and preview untracked junk with git clean -n before removing it. Large committed binaries stay in history unless moved to Git LFS.

Delete the hidden .m2/repository folder for Maven and .gradle/caches for Gradle (after gradle --stop). Dependencies download again on the next build.

Usually not — they're rebuildable and change constantly, inflating every backup. Exclude them in Time Machine's Options and make sure your source code is backed up.

Yes — it holds debugging support files for each device OS version you've connected. Delete old versions; Xcode recreates them if you connect such a device again.

Yes, for retired builds. Archives contain debug symbols needed to read crash reports, so keep those for versions still in use. Delete via Xcode's Organizer.

Command-line and developer tools keep downloads there, such as AI model files and package caches. Check which tool owns each subfolder; deleting a cache is generally safe.

Xcode must expand a compressed download, briefly needing room for both copies — far more than its final size. Clear DerivedData and old simulators, then retry.

GarageBand, iMovie, Pages, Numbers and Keynote can be deleted and re-downloaded free. Core macOS apps like Safari, Mail and Photos are part of the sealed system and can't.

Yes — it's only a downloaded installer and isn't needed after upgrading. Delete it, or keep it on an external drive if you'll make a bootable installer.

Several times the download size while it unpacks and prepares; Software Update says how much more it needs. Free space by emptying the Trash, releasing snapshots and moving big folders off.

In a protected system area you shouldn't touch. Install the pending update or let macOS clean it up; free more space and retry if it fails.

Not any more — removing files inside signed apps can break their code signature and stop them opening, and updates restore them anyway. The space saved is small.

Apps that open at login and helpers that run without a window. Manage them in System Settings → General → Login Items; they use little storage but leftovers can keep running.

Rosetta is small; its translation cache grows only with many large Intel apps. There's no supported uninstall, and it isn't worth chasing for space.

App Store games live in Applications; launchers like Steam keep their own library and can uninstall games or move them to a library folder on an external drive.

Many self-contained apps run from an external drive while it's connected, but apps with system components or self-updaters can break if just dragged. Storage Studio checks which are safe.

It holds apps' working data — databases, downloads, plug-ins — often the only copy. Remove folders of uninstalled apps and use apps' own settings to clear caches.

In Finder's Applications list view, add the Date Last Opened column and sort by it. Check background tools before deleting, as their date may not update.

System Integrity Protection and the sealed system volume stop anyone, including admins, changing macOS files. Reclaimable space is in your files, apps, caches and backups instead.

No — Recovery is how you repair, reinstall or restore your Mac, and it's part of safe startup on Apple silicon. It uses only a small fixed amount of space.

On Intel Macs, use Boot Camp Assistant's option to remove Windows and restore a single volume, after copying off files. Apple silicon uses virtual machines instead.

Not much — a reinstall replaces macOS but keeps your apps, files, caches and backups. Only erasing and starting fresh clears everything, which is rarely necessary.

Fonts are small, but big collections add up. Remove ones you installed and don't use in Font Book; system fonts are protected.

Use the Creative Cloud app to uninstall apps or older versions, and set it to remove previous versions on update. Avoid dragging Adobe apps to the Trash.

For App Store apps, yes — hold an icon until it jiggles and click the X. Other apps must be moved to the Trash from Applications; Library leftovers usually remain.

It's still open, it's a protected part of macOS, it needs an admin password, or it must be removed with its own uninstaller. Quit it and its helpers first.

Downloads are compressed, and after installing, an app's caches, downloads and data grow in your Library — so its real footprint is often far larger than the app itself.

Apple File System, the format macOS uses for its startup disk and recommends for SSDs. It adds clones, snapshots, space sharing between volumes and built-in encryption.

APFS for SSDs used with recent Macs; Mac OS Extended (Journaled) for spinning disks shared with older Macs. Use exFAT if Windows also needs the drive.

exFAT — both macOS and Windows read and write it and it supports big files. It has no journaling or Mac permissions, so prefer APFS for Mac-only drives.

The drive is formatted MS-DOS (FAT32), which can't store files of 4 GB or more. Back it up and reformat as exFAT (Mac and Windows) or APFS (Mac only).

macOS reads NTFS but can't write to it by default. Reformat as exFAT for Mac and Windows, copy over the network, or use third-party NTFS software.

Back up first, open Disk Utility, choose View → Show All Devices, select the drive, click Erase, and choose a format with the GUID Partition Map scheme.

A container is a section of a disk; volumes inside it are what Finder shows, and they share the container's free space instead of having fixed sizes.

In Disk Utility, choose Show All Devices, select the volume, then its container and device, and run First Aid on each. Run it from macOS Recovery for the startup disk.

Usually not — partitions lock space at a fixed size. Add an APFS volume instead, which shares free space. Partition only when a drive needs two different formats.

Case-sensitive APFS treats Report.pdf and report.pdf as different files. Many Mac apps expect the default case-insensitive format, so use that unless a tool requires otherwise.

TRIM tells an SSD which blocks are free so it keeps its speed. Apple's internal SSDs use it automatically; third-party and USB-connected SSDs may not.

Ejecting lets macOS finish writing and close the drive cleanly; unplugging without it can lose recent changes or damage the drive. Quit apps using it first.

An app still has a file open on the drive (a document, media library, indexing or backup). Quit those apps and close Finder windows; Force Eject risks unsaved changes.

A disk image is a file that acts like a drive. A .dmg has fixed contents; sparse images and bundles grow as you add files and need compacting to shrink.

Open System Information, choose NVMExpress or SATA, and check S.M.A.R.T. status; Verified means no reported problems. Keep a backup regardless.

Use GUID Partition Map for nearly everything on a Mac. Master Boot Record is for older devices like some cameras and TVs, usually with exFAT or FAT.

Usually — in Disk Utility, select the Mac OS Extended volume and choose Edit → Convert to APFS. Back up first; it can't be undone and exFAT or NTFS drives must be erased instead.

A small SSD and a large hard drive combined into one disk on some older Macs. Manage space the usual way; an external SSD can noticeably speed up apps and projects there.

Spotlight's index (.Spotlight-V100), the file-change log (.fseventsd) and the drive's Trash (.Trashes). They're usually small; leave them, and empty the Trash with the drive connected.

It copies the whole contents of one volume or disk image onto another, erasing the destination first. Double-check the destination; use Finder to copy only some folders.

macOS transparently compresses many of its own files, but there's no Finder option to compress your files or a whole drive that way.

They're small system volumes macOS manages: Preboot for startup, Recovery for repairs, VM for swap and sleep files, Update for installs. Leave them alone.

In Disk Utility select the volume and click − (Delete APFS Volume). Its contents are erased and the space returns to the container. Never delete the system volumes.

In Disk Utility choose File → New Image → Image from Folder, set the format to compressed, and save. Check it opens before deleting the original.

Yes. A USB-C or Thunderbolt SSD is fast enough to work from and much cheaper per gigabyte than a bigger internal drive; it just needs to be connected for what's on it.

Use an SSD for anything you open or work from (apps, libraries, projects) and a cheaper hard drive for backups and rarely opened archives.

USB-C is just the connector; Thunderbolt and USB4 can be much faster than USB 3, but only if the drive, cable and port all support it. Use the drive's own cable and a direct port.

For occasional transfers, yes, but most SD cards and USB sticks are slow with many small files and less durable. A small external SSD is better for everyday extra storage.

Yes, for archives and shared media; connect with Finder's Go → Connect to Server. It's slower than a direct SSD, and apps like Photos don't support libraries on network shares.

Cloud storage gives access anywhere and online-only files but costs monthly and needs a connection; an external drive is a one-off cost, fast and offline but must be plugged in.

System Information shows the speed the drive is connected at; a disk speed test app measures reads and writes. A slow link usually means the cable, port or a hub.

Mac shows decimal units like the box, so a 1 TB drive shows close to 1 TB minus format overhead. Much less suggests binary units in another tool or an extra partition.

Between different drives Finder copies, so the originals stay and no space is freed. Hold Command while dragging to move, or delete originals after checking the copy.

Check space and format, copy with Finder without interruptions, compare item counts and sizes, open a few files, and only then delete the originals.

Copy finished projects to an external drive, verify them, keep a second copy elsewhere, label them clearly and check archive drives occasionally before deleting originals.

Not as a drive — iPhones and iPads don't appear as disks to a Mac. Use AirDrop or iCloud to share files, and an external SSD or cloud storage for extra space.

Select the drive in Finder and press Command-I, or open it with Finder's status bar shown. Trashed files keep using its space until you empty the Trash with it connected.

Swap files hold memory macOS has moved to disk when RAM is full. They count as System Data, show as Swap Used in Activity Monitor, and clear on restart.

No. RAM is temporary working memory cleared on restart; storage is the SSD that keeps files. When RAM runs short macOS uses storage for swap, so the two interact.

macOS ran short of memory and swap, often from one app using too much memory or very low free disk space. Quit the biggest app, free some disk space and restart if needed.

A file macOS uses to save memory so the Mac can resume after deep sleep or power loss. It's managed by macOS; don't delete or disable it.

Spotlight keeps a modest index on each indexed drive. To rebuild it, add the drive to Spotlight's Privacy list in System Settings, then remove it; adding it alone stops indexing.

Open Activity Monitor's Disk tab and sort by Bytes Written. Backup, sync and indexing processes write a lot after big changes; constant writing by an ordinary app is worth checking.

macOS runs idle-time maintenance: Spotlight indexing, Time Machine, Photos analysis, iCloud syncing and updates. Check Activity Monitor's Disk tab for the process responsible.

Only slightly — with more memory macOS needs less swap on disk, but swap is temporary and rarely why a disk is full. Memory and storage are separate.

Mostly it frees memory. Swap and some temporary files shrink after apps quit or a restart, but caches, downloads and app data stay until you remove them.

Your startup disk is nearly full. Empty the Trash, clear big downloads and old backups, release snapshots, and move big folders or apps to an external drive.

Apps can't save and may quit, updates fail, and the Mac can struggle to log in or start. Files aren't erased, but free a few gigabytes immediately.

Try Safe Mode and delete large files; otherwise use macOS Recovery for First Aid or careful deletions, or another Mac to copy files off. Get help if unsure.

Typically local snapshots, a runaway app cache or log, cloud apps downloading files, device backups or updates, or swap. A space-watching tool helps catch which.

Use the internal drive as working space: photos and documents in the cloud with online-only files, big occasional data on a small external SSD, and old backups and installers cleared out.

Usually purgeable space counted as available but not yet freed, or a FAT32 destination that can't hold files of 4 GB or more. Release snapshots or reformat the drive.

A pre-update snapshot, leftover update files and rebuilt caches and indexes. Most settles within a day or two; delete any leftover Install macOS app.

Installing needs room for the download and for unpacking it, so free more than the app's size, restart, and try again.

On Apple silicon (and T2) Macs, use System Settings → General → Transfer or Reset → Erase All Content and Settings after backing up. Other Macs erase from macOS Recovery.

FileVault encrypts your startup disk, unlocked by your login password or recovery key. On modern Macs it has no noticeable speed or storage cost; keep the recovery key safe.

Right-click the drive in Finder and choose Encrypt, or erase it as APFS (Encrypted) in Disk Utility. You'll need the password whenever it's connected, so don't lose it.

On an encrypted SSD, effectively yes once the Trash is emptied and snapshots holding it are gone. Copies in backups or iCloud remain until you delete them too.

The storage is always hardware-encrypted, but without FileVault it unlocks at startup with no password. FileVault ties unlocking to your login password.

For hard drives, use Disk Utility's Erase with Security Options. For SSDs, erase as APFS (Encrypted) and then erase again, since overwriting isn't reliable on SSDs.

Roughly twice the data you back up, so it can keep a useful history. A smaller drive still works; Time Machine deletes the oldest backups when it's full.

It deletes the oldest backups to make room and tells you. History gets shorter but recent backups stay; if one backup won't fit at all, use a bigger drive or exclude folders.

In System Settings → General → Time Machine, click Options and add folders or drives with +. Excluded items can't be restored from Time Machine.

Not by default — external drives are on Time Machine's exclusion list. Remove a drive from the list in Time Machine's Options to include it; it must be connected during backups.

Yes — add a separate APFS volume for your files and let Time Machine use its own. But if the drive fails you lose both, so back up files that live only there.

Only files actually stored on the Mac. Online-only iCloud files aren't downloaded for backup, and syncing isn't a backup, so keep an independent copy if you need one.

Yes — a NAS with Time Machine support, or another Mac sharing a folder as a Time Machine destination. Add it with Add Backup Disk; the first backup is slow over Wi-Fi.

It copies every changed file in full, so frequently changing big files (VMs, databases, caches, projects) inflate each backup. Exclude ones you don't need versioned.

Use Migration Assistant, choose transfer from a Time Machine backup, and select what to bring. If it won't fit, leave large folders out and keep them on an external drive.

It's a good start, but a single nearby drive can be lost with the Mac. Keep another copy elsewhere — an off-site drive or cloud backup — and include external-only files.

Yes, if the drive could be lost or stolen. Tick Encrypt Backups when adding the disk, and store the password safely — you can't restore without it.

Technically yes, but flash drives are usually small, slow for backups and wear faster. Use a dedicated hard drive or SSD of at least twice your data.

Yes — each Mac keeps separate backups on the shared drive, and space is shared, so size the drive for both Macs plus history.

Open the folder in Finder, enter Time Machine, go back on the timeline, select the file and click Restore. Recent versions may come from local snapshots.

Somewhat — Time Machine stops making local snapshots and their space is released as they expire — but you lose backups. Release snapshots when needed instead.

Hourly backups for 24 hours, daily for a month, then weekly for all earlier months until the disk is full, when the oldest are removed.

No — Time Machine backs up to a disk or a supported network location, not iCloud. iCloud syncs some data but isn't a full Mac backup.

Keep 3 copies of important files, on 2 different kinds of storage, with 1 copy kept off-site — for example the Mac, a Time Machine drive and a cloud or off-site copy.

In list view click the Size column header (add it by Control-clicking the headers). Turn on View → Show View Options → Calculate all sizes so folders sort by size too.

Choose View → Show Status Bar in Finder. The bottom of each window then shows the item count and the space available on that folder's disk.

Press Command-I on any item. Get Info shows its size, where it's stored, its kind and its created and modified dates; for a disk it shows format, capacity and free space.

Choose View → Show Path Bar in Finder to see the folder chain at the bottom of the window. Control-click a file and hold Option to copy its path as text.

Select it and press Option-Command-Delete, or hold Option in the File menu and choose Delete Immediately. It skips the Trash, so it can't be undone.

Command-click to pick individual items, Shift-click for a range in list view, or Command-A for everything, then press Command-Delete to move them to the Trash.

Give candidates a Finder tag (for example a red "Review" tag), then click the tag in the sidebar later to see them all in one list, sorted by size, and decide.

No. Recents is a saved search showing files you used lately where they really live; nothing is copied. Deleting from Recents deletes the real file.

Add the Date Added column in list view and sort by it, or search with Command-F using the Date Added criterion. It shows when files arrived, which suits Downloads best.

Select the file in Finder and press the Space bar for a Quick Look preview, then use the arrow keys to step through other files.

Your own Library holds your settings and caches; the top-level Library holds items shared by all users; the System Library belongs to macOS and is protected. Clean the first two, leave the third alone.

It holds data shared between apps from the same developer, often their real data. Leave folders for apps you still use; leftovers from apps you've removed for good can be deleted.

You can, but they're tiny settings files, so you'll save almost nothing — and you'll reset that app's settings. Look at caches, media and app data for real space.

It's where macOS remembers each app's open windows so they reopen later. It's usually small; deleting an app's entry only stops its old windows reopening.

It's a folder all accounts on the Mac share, and some installers store big content there. Check it via Go → Go to Folder, and remove only items you recognise as no longer needed.

Yes, it's safe; they're usually small and macOS trims old ones itself. A large pile means one app keeps crashing — fix or update that app.

Open the browser's settings, search for "clear browsing data", pick Cached images and files for all time, and confirm. Leave cookies unticked to stay signed in.

Barely — history and cookies are small. The cache and website data are what grow large, so clear those if you want space back.

Go to Safari → Settings → Privacy → Manage Website Data, select sites and click Remove. It signs you out of those sites and removes their offline data.

Yes — each profile keeps its own cache, extensions and site data. Delete profiles you no longer use from the browser's profile manager after exporting anything you need.

Many are built with web technology and bundle their own browser engine plus their own cache. Clear caches in each app's settings, leave unused workspaces, or use the web version of rarely used apps.

By default in a Zoom folder inside Documents, one subfolder per meeting. Delete or move old recordings, or change the save location in Zoom's settings.

Each Office app is large and self-contained. You can't shrink one, but you can delete the apps you don't use; the others keep working.

The list is just a record; files stay in Downloads. Safari's General settings can clear the list automatically, but that doesn't delete files or free space.

Safari (or a double-click) unzips archives but keeps the .zip, so content is stored twice. Delete the .zip once the folder opens fine; you can turn off Safari's auto-open setting.

Yes — apps with Auto Save keep earlier versions (File → Revert To → Browse All Versions). macOS manages and thins them itself, so they rarely use much space.

Press Shift-Command-5, click Options, and pick a folder under Save to (or Clipboard so quick shots aren't saved). It covers screenshots and screen recordings.

In Photos, open Media Types → Screenshots (and Screen Recordings) in the sidebar, select and delete. Then empty Recently Deleted to get the space back.

Keeping both stores every shot twice. Keep RAW if you edit (export JPEGs when needed), JPEG if you don't, and set the camera to shoot only the format you use.

In Preview use Tools → Adjust Size to cut the pixel dimensions, or File → Export as JPEG/HEIC with a lower Quality setting. Save a copy to keep the original.

Open Recently Deleted in Voice Memos and erase the recordings, then set Voice Memos → Settings → Clear Deleted to a shorter period.

No — Photos keeps the full original so the trim can be undone. Export the trimmed clip and delete the original, or trim in QuickTime Player and save the shorter file.

A little — Photos keeps the original alongside each edit so you can revert. Export the edit and delete the original if you want one smaller file, at the cost of undo.

In your Library under Application Support → Steam → steamapps. Steam's Storage settings show each game's size and let you uninstall games you've finished.

In Steam's Storage settings, add the external drive as a library and move installed games to it. Use a fast APFS SSD and keep it connected while playing.

Yes. Shut the VM down fully, move its bundle to a fast external SSD, and open it from there. Keep the drive connected while the VM runs.

Yes — every snapshot keeps the changes made since it was taken, so old snapshots add up. Delete the ones you no longer need in the VM app's snapshot manager.

Virtual disks grow but don't shrink on their own. Empty the guest's trash, delete old snapshots, then use your VM app's reclaim or compact option with the VM shut down.

List versions (nvm ls, pyenv versions, rbenv versions) and uninstall the ones no project pins. Each removed version takes its global packages with it.

Each virtual environment is a folder (.venv, venv, env) holding its own packages. Delete ones you don't use; recreate them from requirements.txt when needed.

Run conda clean --all to drop cached packages, list environments with conda env list, and remove unused ones with conda env remove -n plus the name.

Delete that version's folder in Applications and its folder in /Library/Frameworks/Python.framework/Versions. Don't touch the Python that comes with Apple's developer tools.

List JDKs with /usr/libexec/java_home -V, then delete unneeded ones from /Library/Java/JavaVirtualMachines. Use Homebrew to remove any it installed.

You can delete /Library/Developer/CommandLineTools, but git, Homebrew and compilers need it. Reinstall any time with xcode-select --install.

Run gem cleanup to remove old gem versions and composer clear-cache to empty Composer's download cache. Project vendor folders can be deleted and reinstalled.

Run pnpm store prune to drop unreferenced packages and bun pm cache rm to clear Bun's cache. Packages re-download on the next install.

Run flutter clean in each project to delete its build folder, and dart pub cache clean to empty the shared package cache. Both rebuild when needed.

Remove unneeded simulators first, delete Xcode from Applications, then clear the build-data and device-support folders in your Library's Developer folder. Keep Archives if you publish apps.

Uninstall editor versions you don't need from Unity Hub, and delete a closed project's Library folder (Unity rebuilds it). Never delete Assets, Packages or ProjectSettings.

List boxes with vagrant box list, drop old versions with vagrant box prune, and delete a box with vagrant box remove; destroy unused machines with vagrant destroy.

Free more room than the download size — empty the Trash, delete old downloads and installers, restart to release temporary space, then try again.

In System Settings → General → Software Update, click the info button next to Automatic updates and turn off Download new updates when available.

Yes — once a .pkg has run, the software is installed and the package isn't needed. Delete it, or archive it on an external drive if you might reinstall offline.

No — the App Store installs straight into Applications and cleans up, so there's no installer to remove. Delete apps you don't use to reclaim their space.

No — major upgrades are optional and listed separately. Stay on your version with its security updates, and free plenty of space before you do upgrade.

In System Settings → Users & Groups, open the account's info and choose Delete User, then pick Delete the home folder to actually free its space (copy anything needed first).

In System Settings → Accessibility → Spoken Content, open Manage Voices for the System Voice and untick voices you don't use. They can be downloaded again any time.

Open System Settings → General → Language & Region → Translation Languages and remove the languages you don't need; they can be downloaded again later.

Yes — remove unused printers in System Settings → Printers & Scanners, then delete the maker's folder in /Library/Printers or run its uninstaller. macOS re-downloads drivers when needed.