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Compress files on a Mac to save space: when it's worth it

How to compress files on a Mac with Finder and Disk Utility, how much a ZIP really saves by file type, and when compressing is worth it.

Mac storage basics · Published · 25 min read
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To compress files on a Mac, Control-click a file or folder in Finder and choose Compress. Finder makes a .zip file next to the original, and the original stays where it was. To get the contents back, double-click the .zip file.

Whether it saves space depends almost entirely on what's inside. Text, spreadsheets, logs and uncompressed images shrink a lot, often to a quarter of their size or less. Photos, videos, music and most app documents are compressed already, so zipping them saves next to nothing, and the archive can even come out slightly larger.

Compressing is worth it for finished work you want to keep but rarely open, for sending a folder as one file, and for packing data before it goes to an external drive. It isn't worth it for files you use every day, for photos and video, or for anything in the Trash.

And it doesn't free a single byte by itself. A ZIP file is a copy, so your Mac holds more until you check the archive and move the originals to the Trash. This post covers each step, with measurements of what compressing saves for each kind of file.

How to compress files on a Mac with Finder

Finder's Compress command is built into macOS and needs no extra app. It makes standard ZIP files, and Apple notes that compressed files take less space, which helps with backups and with sending information over the internet.

How do you zip a file or folder?

  1. In Finder or on the desktop, select the file or folder.
  2. Control-click it and choose Compress, or choose File › Compress.
  3. Wait for the .zip file to appear in the same folder.

To put several items into one archive, select them all first, then Control-click any of them. Apple's guide says a single item becomes a .zip file with the item's name, and several items become one file called Archive.zip. Rename it right away, so you know later what's inside.

What does Compress actually create?

A new file, with everything you selected packed inside and compressed. Nothing is moved or deleted: your files stay exactly where they were, and the archive sits beside them.

That's why compressing alone never frees space. Right after you zip a 2 GB folder, your Mac holds the folder plus the archive. The space comes back only when the originals go to the Trash and the Trash is emptied.

How do you open a .zip file?

Double-click it. Apple says the unzipped item appears in the same folder as the .zip file, and that you can delete the .zip file afterwards if you want. Opening an archive doesn't change it, so you end up with two copies again.

If a .zip file won't open, Apple's first suggestion is to make sure there's enough free space for the unzipped item. If someone sent it to you, it may be damaged; Apple suggests asking them to zip it again and send it once more.

Why can't you compress a file or folder?

Usually because of permissions. Apple's guide to this problem says to select the item, choose File › Get Info, open Sharing & Permissions, and check what your user name is allowed to do. If you can't change it, ask the Mac's administrator or the file's owner.

Compressing also needs free space for the archive itself. On a nearly full disk, making room first is the simpler fix.

Can you password-protect a ZIP file in Finder?

Not with Finder's Compress command, which has no password option. macOS offers two other routes: Archive Utility can make an Apple Encrypted Archive with a password, and Disk Utility can make an encrypted disk image. Both are covered below.

Archive Utility: the app behind Compress

When you compress or open an archive in Finder, macOS hands the job to a small app called Archive Utility. It opens, does its work and quits, so most people never see it. It has settings worth knowing, though.

Where is Archive Utility?

It lives in /System/Library/CoreServices/Applications, a folder macOS keeps out of sight. The quickest way to open it is Spotlight: press Command-Space, type Archive Utility and press Return. Then choose Archive Utility › Settings….

Leave the app where it is. It's part of macOS, on the protected system volume, and Finder relies on it to make and open archives.

Which Archive Utility settings matter?

The settings window has two halves: one for expanding archives and one for making them. These are the choices on a Mac running macOS 27, checked in October 2026.

SettingChoicesWhat it changes
Save expanded filesThe archive's folder, or one you pickWhere opened archives go
After expandingLeave the archive, move it to the Trash, delete it, or move it to a folderWhat happens to the archive
Keep expanding if possibleOn or offOpens an archive inside an archive
Save archivesThe files' folder, or one you pickWhere new archives go
After archivingLeave the files, move them to the Trash, delete them, or move them to a folderWhat happens to the originals
Use archive formatCompressed, regular, Zip, Apple Archive, Apple Encrypted ArchiveWhat Create Archive makes

The format menu sets what Archive Utility's own File › Create Archive… command makes. Its File › Expand Archive… command opens an archive you choose, the same way a double-click does.

Should archives go to the Trash after expanding?

For downloads, move archive to Trash is a sensible choice. Most archives you open came from the web, and once their contents are out, the archive is a second copy. Moving it to the Trash, rather than deleting it, still lets you put it back.

Avoid delete archive and delete files archived. Both skip the Trash. If an archive turns out to be damaged or incomplete, deleting its source straight away leaves nothing to fall back on.

Which formats can Archive Utility open?

More than ZIP. On macOS 27, its own list of the file types it handles includes the formats below. Double-click any of them, and Archive Utility expands it.

FormatUsual extensionsCan it make one?
ZIP.zipYes; Finder's Compress makes these
CPIO and CPGZ.cpio, .cpgzYes
Apple Archive.aarYes, plain or encrypted
tar, gzip, bzip2, xz.tar, .gz, .tgz, .bz2, .xzNo, it only opens them
7-Zip.7zNo, it only opens them
XIP.xipNo, it only opens them
RAR.rarNo, and it can't open them

RAR isn't on the list, and Archive Utility says outright that StuffIt archives aren't supported. For those, you need a third-party app. Choose a well-known one from the App Store or the developer's own site.

Cardboard box and paper bags on table in cluttered workspace with shelves.
Archiving finished work you rarely open is where compressing earns its keep. Photo: Anna Shvets on Pexels

How much does compressing save? It depends on the file

Compression finds patterns in data and writes them down more briefly. A ZIP file uses lossless compression: expand it and you get back every byte exactly as it was. How much it saves depends on how much pattern is left in the data.

What compresses well?

Files with lots of repetition. Plain text, CSV exports, logs, code and uncompressed images all have plenty of it. A log file that repeats the same words on every line can shrink to a sixth of its size.

To see it for ourselves, we made a set of synthetic test files in a temporary folder on one Mac running macOS 27, in October 2026, and zipped each one with macOS's built-in tools. No real person's files were involved. These are the documents.

Test fileOriginalZippedSaved
App log, plain text21.1 MB3.3 MB84%
Sales data, CSV15.6 MB3.6 MB77%
Plain text file3.0 MB0.7 MB77%
The same text as a Word .docx0.9 MB0.9 MB0%

The last row is the interesting one. Saving the 3 MB text file as a Word document already brought it down to 0.9 MB, because a .docx file is compressed inside. Zipping it again found nothing left to remove.

Why do Word, Excel and other app documents barely shrink?

Because they're archives already. Microsoft says its Open XML formats, which include .docx, .xlsx and .pptx, use zip compression to store documents, and that files can be up to 75 percent smaller in some cases. Zipping such a file compresses it twice, and the second pass gains almost nothing.

Many other apps store their documents compressed too, and documents full of photos or video are mostly media. Expect little from zipping a document made in a modern app. The exceptions are plain text, CSV and older formats such as .doc.

Why do photos and videos barely shrink?

Because JPEG, HEIC, PNG, H.264 and HEVC are compression formats themselves. They've already squeezed out the patterns a ZIP file looks for. What's left looks random to a ZIP tool, and random data can't be made smaller.

JPEG, HEIC and the video formats go further than a ZIP file ever could, by throwing away detail your eyes are unlikely to miss. That's lossy compression, and it's why a photo from a phone takes a few megabytes rather than tens of megabytes.

Here's the media from the same test, all synthetic files made on that Mac.

Test fileOriginalZippedSaved
Photo, uncompressed TIFF36.9 MB32.3 MB12%
Same photo, PNG25.1 MB25.1 MBNone; it grew 8 KB
Same photo, JPEG3.6 MB3.5 MB1%
Same photo, HEIC3.0 MB3.0 MB0%
20-second video, H.26430.5 MB30.5 MBNone; it grew 9 KB
Same video, HEVC15.3 MB15.3 MBNone; it grew 4 KB
One minute of audio, AAC1.0 MB1.0 MB1%
Random data, like an encrypted file21.0 MB21.0 MBNone; it grew 7 KB

Even the uncompressed TIFF shrank only 12%. Our test photo had fine grain all over it, like the noise in a real photo, and grain is close to random. A test image of flat color bars, more like a screenshot, went from 8.0 MB as a TIFF to under 0.1 MB zipped.

One photo, five ways

The chart puts that photo's sizes side by side. Choosing a better format did far more than zipping: the HEIC copy is less than a tenth of the TIFF, while zipping the TIFF trimmed only an eighth.

One 12-megapixel test photo, saved five ways
  • TIFF, uncompressed36.9 MB
  • TIFF, zipped32.3 MB
  • PNG25.1 MB
  • JPEG, quality 803.6 MB
  • HEIC3 MB

Measured in October 2026 on one Mac running macOS 27, using a synthetic test image made for this post, not a real photo.

Does a folder of mixed files compress well?

Only as well as the files inside it. A ZIP file compresses each file on its own, so a folder's saving is the sum of its files' savings.

In our test, a folder of all twelve test files went from 176.9 MB to 140.3 MB, a 21% saving. Most of it came from the three text files, and the rest from the TIFF.

That's the rule of thumb to take away. Before compressing a folder to save space, look at what's in it. A folder of photos and videos stays the same size; a folder of exports and logs can shrink to a fraction.

Compressed disk images in Disk Utility

A disk image is a single file that holds a whole volume, which macOS opens like a drive. Disk Utility can make one from any folder, and one of its formats is compressed. It's an alternative to a ZIP file for archiving.

How do you make a compressed disk image from a folder?

  1. Open Disk Utility, in the Utilities folder inside Applications.
  2. Choose File › New Image › Image from Folder.
  3. Select the folder and click Open.
  4. Enter a name, choose where to save the image, and choose the compressed format from the Image Format menu.
  5. Click Save, then Done.

Disk Utility saves the image and opens it, so it appears on the desktop and in the Finder sidebar. Apple notes that an image made this way holds only the folder's data, not free space. To open it later, double-click it.

On macOS 27, the menu names the formats more technically, such as Read-only Compressed Image (ULFO). That's the one to choose for an archive.

Which image format should you choose?

Apple's guide describes these formats. The compressed one is the only one that saves space; the others suit different jobs.

FormatCompressedAdd files laterGood for
Read-onlyNoNoQuick to make and open
CompressedYesNoArchiving a finished folder
Read/writeNoYesA container you keep editing
Sparse bundleNoYes, it growsA growing archive on a drive
DVD/CD masterNoNoBurning with third-party apps

Apple describes the compressed format as smaller than the original data and read-only. Once it's made, nothing can be added or changed, which suits an archive: what you checked is what you keep.

What's a sparse bundle for?

A sparse bundle grows as you add files and uses only the space its contents need. Apple describes it as an expandable image like a sparse disk image, with its directory data stored differently, and it uses the .sparsebundle extension. You make one with File › New Image › Blank Image.

It isn't compressed, so it saves no space by itself. Its use is as a container you keep adding to, such as an encrypted archive on an external drive.

Can you encrypt an archive?

Yes, with a disk image. In the same dialog, click the Encryption menu and choose an option. On macOS 27 the choices are 128-bit AES and 256-bit AES, which Disk Utility marks as recommended. It asks you for a password when you pick one.

Apple's warning is worth repeating: if you forget the password, you won't be able to open the disk image and view any of the files. Save it in the Passwords app or another password manager before you remove the originals.

Archive Utility's Apple Encrypted Archive format also takes a password, with an option to store it in your keychain. Either way, the password is the only key.

ZIP or disk image: which is better for an archive?

In our test, ZIP came out slightly smaller every time. Disk Utility's compressed image, made with the same synthetic files, was a little larger, and for media it was larger than the original. Archive Utility's Apple Archive format landed in between.

Test folderOriginalZIPCompressed disk imageApple Archive
Text files only39.6 MB7.6 MB8.7 MB8.5 MB
Photos, video and audio only53.4 MB53.4 MB54.9 MB53.4 MB
All twelve test files176.9 MB140.3 MB143.8 MB141.8 MB

So choose by what you need rather than by size. ZIP is the most widely used of the three. A disk image can be encrypted and opens like a drive, so you can copy out one file without expanding everything. Apple Archive, which Apple's developer documentation describes as multithreaded and able to keep file attributes, is mainly for Macs.

Smaller copies: HEIC, HEVC and exporting

For photos, video and PDFs, the way to save space isn't a ZIP file but a smaller copy: a more efficient format, fewer pixels or lower quality. This is lossy, so the copy is never quite the original. Decide what you can give up before you start.

Why are HEIC and HEVC better than zipping?

Because they compress the picture itself. Apple says HEIF, the format behind .heic photos, and HEVC, also called H.265, offer better compression than JPEG and H.264. They keep the same visual quality while using less space on your devices and in iCloud Photos.

On iPhone, the setting is Settings › Camera › Formats. High Efficiency records HEIF and HEVC, and Most Compatible records JPEG and H.264. Unless something you use can't open the newer formats, High Efficiency saves space at the source, before anything reaches your Mac.

How do you export smaller photos from Photos?

  1. In Photos, select the photos.
  2. Choose File › Export › Export [number] Photos.
  3. Click the Photo Kind menu and choose HEIC or JPEG.
  4. Click the arrow beside it to set JPEG Quality and Size.
  5. Click Export and choose a folder.

Apple describes JPEG as making small files suitable for websites and other photo apps, and HEIC as a more efficient way to store images without compromising quality. TIFF and PNG are lossless, so they make much larger files.

For videos, the same menu's Export [number] Videos offers a Movie Quality of 480p, 720p, 1080p or 4K. A lower setting makes a smaller file and a softer picture.

Should you replace your library with smaller copies?

Usually not. Exporting makes copies, and the originals stay in your Photos library. Deleting the originals to keep only smaller exports loses detail for good, and the exported copies sit outside Photos, away from your albums and memories.

To make the library itself smaller, use Photos' own tools: Optimize Mac Storage with iCloud Photos, or moving the library to an external drive. Never compress the library or anything inside it. The post on what fills the Photos library explains both.

How do you make a smaller copy of a video in QuickTime Player?

  1. Open the video in QuickTime Player.
  2. Choose File › Export As, then a size: 4K, 1080p, 720p or 480p.
  3. For 4K or 1080p, choose Smaller File Size to use HEVC, rather than Greater Compatibility, which uses H.264.
  4. Choose a name and a folder, and save.

Apple notes that QuickTime Player exports .mov files, and that the exact resolution and data rate depend on the original. Fewer pixels and HEVC together usually save the most. Audio Only keeps just the soundtrack, as an AAC audio file.

How do you shrink a PDF in Preview?

  1. Open the PDF in Preview.
  2. Choose File › Export.
  3. In the Quartz Filter menu, choose Reduce File Size.
  4. Enter a new name in Export As, so the original stays, and click Save.

Apple warns that a compressed PDF may be of lower quality than the original, and that the size and image quality vary with the options you choose. Check a scanned page or a photo at full size before you replace anything.

The same dialog has two more checkboxes on macOS 27, Optimize images for screen and Save images as JPEG, which Apple lists as ways to reduce the size. A PDF of plain text is usually small already; these options help most with scans and photo-heavy documents.

How do you resize images in Preview?

  1. Open the image in Preview and choose Tools › Adjust Size.
  2. Make sure Resample image is selected.
  3. Enter a smaller width or resolution, or choose a size from Fit into, with Scale proportionally selected.
  4. Check the resulting size shown at the bottom, then click OK.

To resize several at once, open them in one Preview window, select them in the sidebar and choose Tools › Adjust Size. To change the format instead, choose File › Export and pick HEIC or JPEG from the Format menu; JPEG has a quality setting.

Preview saves changes to the file you opened. To keep the full-size original, choose File › Duplicate first, or use File › Export to save the smaller copy under a new name.

What do you give up?

MethodLosslessWhat you loseBest for
ZIP or Apple ArchiveYesNothingText, data, finished projects
Compressed disk imageYesNothingEncrypted or browsable archives
HEIC or HEVC copyNoA little detailPhotos and video you'll view
Smaller size or resolutionNoPixels, for goodSharing, web, email
Preview's Reduce File SizeNoImage quality in PDFsScans you only need to read
Cork-covered notebook topped with printed photographs on a white desk, conveying travel memories.
Photos are compressed already, so a ZIP file barely changes their size. Photo: PNW Production on Pexels

Your Mac already compresses some files

macOS has its own compression, built into the file system, that you never see. A compressed file opens and reads exactly like any other, because macOS expands it as it's read. Apple's developer documentation names filesystem compression among the features of APFS, the file system every modern Mac uses.

Where does macOS use it?

Mostly on its own files. On one Mac running macOS 27, measured in October 2026, the built-in apps in /System/Applications held about 1.3 GB of data but took about 0.7 GB on disk. Calculator alone holds about 5 MB of data in about 2.3 MB.

That's free space you already have, and it's one reason macOS itself takes less room than its files add up to.

Why does Get Info show a smaller size on disk?

Finder's Get Info window shows an item's size in bytes and, in brackets, the space it takes on disk. When the second number is much smaller, compression is one likely reason. A sparse file, which records empty space without storing it, is another.

The space on disk is the number that matters for free space. Disk analyzers that add up file sizes without it can report more than a folder really takes.

Can you turn it on for your own files?

No. macOS has no setting, menu or switch for it, in Finder, Disk Utility or System Settings, and Apple doesn't document it as a feature for users. You'll mostly find it on macOS's own files.

Some third-party utilities apply it to other folders, usually apps, but an app update can replace the compressed files with ordinary ones. Like removing language files from apps, it trims the apps themselves rather than the documents and media that usually fill a Mac.

When to compress files on a Mac, and when not to

Compressing is a tool for files you're finished with. Whether it's worth the effort comes down to three questions: will you open these files soon, are they compressed already, and is there a better way to make room?

Archiving finished projects

This is the best case. A finished project folder, with its text, data, exports and source files, may shrink well, and one archive is tidier than thousands of loose files. Before you zip, delete what the project's app can rebuild, so you don't archive it.

Video projects are the clearest example: render files are regenerated on demand. The post on the render files iMovie and Final Cut make covers removing them inside each app; never open or compress the library package itself.

For photographers, Lightroom Classic's catalog and previews have their own settings worth checking before you archive a year of work.

Sending files to someone

Compressing bundles a folder into a single attachment and keeps its structure intact on the other end. Apple notes that compressed files help when sending information over the internet.

For photos and video, the saving is minimal, so zip them only to bundle them. AirDrop sends items directly to nearby Apple devices, with no archive needed.

Moving files to an external drive

Compressing a large set of text or data files before you move them means less to copy and less space used on the drive. For a few large media files, it adds time and saves nothing, so copy them as they are.

Either way, the files on the drive should open before the copies on your Mac go. If the drive holds the only copy, it isn't a backup; keep a second copy somewhere else, such as a Time Machine disk or cloud storage.

What about files in iCloud Drive?

Zipping doesn't move anything off your Mac. If your Desktop and Documents folders sync with iCloud Drive, a better way to make room is to keep files only in iCloud: Control-click a file or folder in Finder and choose Remove Download.

Archives you make in those folders count against your iCloud storage too, and Apple notes that deleting a file there deletes it on every device signed in to the same Apple Account. The post on Desktop & Documents in iCloud explains how that sync works.

SituationCompress?Why
Finished project you rarely openYesText and data shrink into one tidy file
Folder of documents to sendYesOne attachment, structure kept
Logs, CSV and text exportsYesOften shrink to a quarter or less
Photos and videosNoAlready compressed; export smaller copies
Files you open every weekNoYou'd expand them each time
Items in the TrashNoEmpty the Trash instead

When compressing doesn't help

Some of the most common reasons people reach for Compress are the ones where it does nothing for space, or causes trouble.

Files you use every day

An archive has to be expanded before you can use what's inside, and expanding it makes a full copy again. Zipping a folder you open every week means unzipping it every week, with two copies on disk each time. Leave active work as it is.

Photos, music and video

As the test above shows, JPEG, HEIC, PNG, H.264, HEVC and AAC files stay the same size in a ZIP file. That includes screenshots, which macOS saves as .png files, and screen recordings, which it saves as .mov files. Deleting the ones you don't need does more; see where screenshots and screen recordings pile up.

Backups

Don't zip Time Machine backups, iPhone backups or a backup folder an app manages. Each one's owner expects its own format: Finder can't restore an iPhone from a ZIP file, and Time Machine manages its own disk. Changing them by hand risks the one copy you'd rely on.

The Trash

Compressing items in the Trash makes a new copy outside it and frees nothing. If you're sure about what's in the Trash, empty it; that's what frees the space. If you're not sure, leave it until you are.

Apps

Zipping an app you use saves nothing, because you'd have to expand it again to open it. Keep the apps you use in Applications, and remove the ones you don't, with the app's own uninstaller if it has one.

Does compressing files make a Mac faster?

No. At best it frees space, not speed. A Mac with very little free space can struggle to install updates or save large files, so room helps with those, but apps don't run faster because some files are zipped. Expanding an archive takes time of its own.

A collection of sleek tech gadgets on a minimalist desk, showcasing modern technology.
Check the archive opens on its new drive before the originals go to the Trash. Photo: Cats Coming on Pexels

Keep the original until the archive is checked

The moment of risk isn't compressing; it's deleting the originals afterwards. A damaged or incomplete archive is rare, but nothing warns you about one until you try to open it, and by then the originals may be gone.

How do you check an archive is good?

  1. Select the original folder, choose File › Get Info, and note its size and number of items.
  2. Copy the archive to where it will live, such as an external drive.
  3. Double-click the copy there to expand it.
  4. Compare the expanded folder with the original: size, number of items, and a few files opened with Quick Look.
  5. Move the expanded test copy to the Trash.

For a disk image, double-click it, browse the volume that appears and open a few files. Eject it in the Finder sidebar when you're done.

When can you delete the originals?

Once the archive opens on its new drive and holds what you expect. Move the originals to the Trash rather than deleting them for good; until the Trash is emptied, File › Put Back returns each item to where it was.

Leave them in the Trash for a few days if you can. If you need the space now, empty it once the archive has passed the check above.

When is the space actually freed?

Only when the originals leave the Trash. Files in the Trash still take space until you empty it. Even then, Time Machine's local snapshots can hold on to deleted files for a while; see why deleting files doesn't always free space.

Mistakes to avoid

  • Deleting the originals before testing the archive. Expand a copy first, preferably on the drive where the archive will live.
  • Setting Archive Utility to delete files after archiving. It skips the Trash, so a bad archive leaves nothing behind.
  • Zipping media to save space. Photos and videos stay the same size; export smaller copies instead.
  • Compressing inside app libraries. Photos, Music, Final Cut and iMovie libraries are managed by their apps, so use the app's own tools.
  • Encrypting without saving the password. A forgotten password locks the archive for good.
  • Keeping the only copy of an archive on one drive. Drives fail, so keep a second copy.
  • Pasting compression scripts from the web. Commands that compress and delete in one go skip the Trash and can't be undone.

Finding files worth archiving

The best candidates are large, old and finished: project folders you haven't opened in a year, exported data, old logs. Finder can find them without any extra app.

How do you find large, old files in Finder?

  1. In Finder, press Command-F.
  2. Click the Kind menu, choose Other…, select File Size, and click OK. Set it to is greater than 500 MB.
  3. Click the add button, and add Last opened date is before a date a year ago.
  4. Sort the results by size.

Look at what each result is before deciding. A large old video won't shrink in a ZIP file, so it's a candidate for an external drive or the Trash, not for compressing. The post on finding large files on a Mac goes through more search criteria.

What about archives you already have?

Downloads tends to collect archives you've already opened: a .zip file next to the folder it expanded into. Once you've checked the expanded copy is there and complete, the archive is a second copy. Cleaning up the Downloads folder covers how to sort those out.

The reverse also happens: an old archive may be the only copy of what's inside. Expand it and look before you move it to the Trash.

Which folders are worth checking?

Where to lookLikely candidatesWhat usually helps
~/DocumentsFinished projects, old exportsCompress text and data
~/DownloadsArchives, installers, datasetsRemove second copies
~/DesktopScreenshots, temporary exportsRemove or file away
~/MoviesFinished videos and exportsMove to an external drive
~/PicturesExports outside the Photos libraryMove, or remove duplicates

Work inside these folders, never on the folders themselves. Documents, Desktop and the rest belong to macOS and your apps, and they stay where they are.

How the app does it

Wombit is a native Mac app that shows what's using your storage and explains every item in plain language. It scans the whole disk or any folder, reading only names, sizes and dates, and file names and paths never leave your Mac. Making archives is left to Finder and Disk Utility.

The map is the home screen: a treemap and a sunburst show which folders and files are large, with a list and search beside them. Quick Look and Reveal in Finder work on every item, so you can open a candidate in Finder and compress it there. Hard links and APFS clones count once.

Its catalog explains two kinds of files this post is about: Archives in Downloads, which you may already have expanded, and Large files not changed in a year, files of 500 MB or more in your home folder that haven't changed for a year. Both are Review first: either may be the only copy of something, so nothing starts checked, and the app waits for your choice.

  • ~/Downloads/*.{zip,ZIP,tar,gz,tgz,bz2,xz,7z,rar}

    Archives in Downloads

    Compressed archives you downloaded, such as .zip files. Often you've already opened them and have the extracted copy.

    Review first · Moves it to the Trash

  • ~/**/*

    Large files not changed in a year

    Files of 500 MB or more in your home folder that haven't changed for a year, such as old videos, disk images and archives.

    Review first · Moves it to the Trash

When you do remove something, it goes to the Trash with a review sheet first and a log afterwards, and Undo and Put Back work until you empty the Trash.

The scan, the map and the explanations are free. Cleanup and the Apple Data actions for large old files are PRO: one payment of $4.99 with lifetime access. Every Pro tool's review is free to open, so you see what would go and why before you buy.

Frequently asked questions

Does compressing files save space on a Mac?

Only for some files, and only after you remove the originals. Text, spreadsheets, logs and uncompressed images often shrink to a quarter of their size or less, while photos, videos, music and most app documents barely change. A ZIP file is a copy, so the space comes back only when the originals leave the Trash.

Why didn't my ZIP file get any smaller?

Because what's inside is compressed already. JPEG, HEIC, PNG, H.264 and HEVC files, and documents such as .docx and .xlsx, have had their patterns squeezed out, so a ZIP file has nothing left to remove. The archive can even be a few kilobytes larger than the original.

Is it safe to delete the original files after compressing them?

Yes, once you've checked the archive. Copy it to where it will live, expand that copy, and compare the item count and size with the original. Then move the originals to the Trash, where Put Back still works until you empty it.

Can I password-protect a ZIP file on a Mac?

Not with Finder's Compress command, which has no password option. Disk Utility can make an encrypted disk image with 128-bit or 256-bit AES, and Archive Utility can make an Apple Encrypted Archive with a password. If you forget the password, the files can't be opened.

Can a Mac open RAR and 7z files?

On macOS 27, Archive Utility's list of formats includes 7-Zip, tar, gzip, bzip2, xz and Apple Archive as well as ZIP, but not RAR. For RAR files you need a third-party app. Choose a well-known one from the App Store or the developer's own site.

Does macOS compress files automatically?

Yes, some. APFS, the Mac's file system, has its own transparent compression, and macOS uses it for many of its own files, which read normally. There's no setting to turn it on for your files, in Finder, Disk Utility or System Settings.

Should I compress my photos to save space?

Not with a ZIP file, which barely changes their size. To save space on photos, use HEIC rather than JPEG, export smaller copies for sharing, or use Photos' own Optimize Mac Storage with iCloud Photos. Never compress the Photos library or anything inside it.

Does compressing files make my Mac faster?

No. At best it frees space, not speed. Having room helps a Mac install updates and save large files, but apps don't run faster because some files are zipped, and expanding an archive takes time of its own.

Sources

  1. Zip and unzip files and folders on Mac · Apple
  2. Create a disk image using Disk Utility on Mac · Apple
  3. Reduce the size of a PDF in Preview on Mac · Apple
  4. Using HEIF or HEVC media on Apple devices · Apple
  5. Export movies in QuickTime Player on Mac · Apple
  6. Open XML Formats and file name extensions · Microsoft