Photos taking up too much space on Mac? What's really in the library

Photos taking up space on a Mac almost always means one thing: the Photos library, a single package in your Pictures folder. It holds every original photo and video you've imported, the edits you've made, and the previews and database Photos builds so it can show them quickly.

If you use iCloud Photos with Download Originals to this Mac, the library keeps a full copy of everything you have in iCloud. With Optimize Mac Storage, it keeps smaller versions, but only once your Mac needs the space, and some full-size files always stay.

So the fixes are few, and each follows Apple's own steps: switch to Optimize Mac Storage, delete what you don't want and empty Recently Deleted, merge duplicates, or move the library to an external drive.

The one thing never to do is open the library in Finder and delete files inside it. Photos manages that package as a database, and changing it from outside can damage the whole library.

How much space Photos is taking up on your Mac

Start by measuring, because the answer decides the fix. A library of a few gigabytes isn't worth much effort. One of several hundred gigabytes, on a Mac with a small internal disk, is usually the largest single thing on it.

Where do you see the size of the Photos library?

Choose Apple menu › System Settings, click General, then click Storage. The Photos category shows how much your System Photo Library takes. That's the library Photos opens by default and the only one that syncs with iCloud Photos.

For a second opinion, open your Pictures folder in Finder, select Photos Library, and choose File › Get Info. If you're not sure where your library is, open Photos, choose Photos › Settings, click General, and click Show in Finder under Library Location.

Why don't Finder and Storage settings agree?

They count different things, at different times. Storage settings works its numbers out in the background and counts only the System Photo Library under Photos. Finder measures the package you selected, when you ask. A few gigabytes of difference is normal and doesn't mean anything is wrong.

If the gap is large, or your free space looks wrong everywhere, the guide to why Finder, Storage settings and Disk Utility disagree explains purgeable space and the other usual causes.

Do you have more than one library?

Many Macs do, without their owners knowing. A library from an older Mac, an iPhoto library from years ago, or a test library made once and forgotten can each hold tens of gigabytes. Only one of them shows under Photos in Storage settings.

To see the libraries Photos knows about, quit Photos, then hold the Option key while you open it. The Choose Library dialog lists them, and marks the one in use as the System Photo Library. Click Other Library to look for any it doesn't list.

What's really in the Photos library?

Photos keeps everything in one package, named Photos Library by default, at ~/Pictures/Photos Library.photoslibrary. In Finder it looks like a single file. Inside it are thousands of files in folders that only Photos understands.

Originals, edits, previews and the database

The library holds four kinds of thing. Your originals are the photos and videos exactly as they were imported. Your edits are kept beside them, because Photos always keeps the original so you can choose Image › Revert to Original.

Previews and thumbnails let Photos show a grid of thousands of pictures at once. A database records albums, people, places, keywords and everything else you've organized.

In most libraries the originals take the most room, because previews and thumbnails are smaller versions of them. That's why deleting items, or letting iCloud keep the originals, is what makes a difference.

What's inside	Where it comes from	How to make it smaller
Original photos and videos	Every import, from iPhone, camera or Finder	Delete items in Photos, or Optimize Mac Storage
Edited versions	Changes you make in Photos or another editor	Kept with the original; deleting the item removes both
Previews and thumbnails	Made by Photos as you browse	Nothing: Photos manages them
The database	Albums, people, places, keywords	Nothing: it's small next to the originals
Full-size copies kept after viewing	Originals downloaded from iCloud to view or edit	Optimize Mac Storage removes them when space is needed

Why videos take most of the room

A minute of video takes far more space than a photo, and phones make it easy to record long clips at high resolution. That's why the Videos collection is the first place to look when a library is larger than you expect.

Live Photos add to it quietly. Each one is a still image plus a short video; Photos exports a Live Photo as two separate files for that reason. With Optimize Mac Storage on and space running low, Photos keeps Live Photos on your Mac as still images, and plays the whole thing when you open one.

What isn't in the library

Some photos on your Mac are outside Photos altogether. Pictures someone sends you with AirDrop land in Downloads, and Storage settings counts them under Documents, not Photos. Attachments in Messages live in Messages' own folder. Files you import with Copy items to the Photos library turned off stay where they were.

These aren't reduced by anything you do in Photos. They're covered further down, under the other places photos pile up.

Why Photos takes so much space with iCloud Photos on

The most common surprise is a large library on a Mac that uses iCloud Photos. The reason is usually one setting, and how it behaves when your Mac has plenty of free space.

Download Originals or Optimize Mac Storage?

Open Photos, choose Photos › Settings, and click iCloud. With iCloud Photos selected, you choose one of two options.

Setting	What stays on this Mac	What it costs
Download Originals to this Mac	A full-size copy of every photo and video, as well as in iCloud	The most space: every original, on the Mac and in iCloud
Optimize Mac Storage	Smaller versions when space is limited; originals in iCloud	An internet connection to open or edit an original
iCloud Photos off	Everything in this library; changes no longer sync	No sync: back the library up yourself

Download Originals to this Mac is the setting to check first. If it's selected, your library is meant to be as large as your whole collection. Choosing Optimize Mac Storage is the biggest single change most people can make.

Why Optimize Mac Storage doesn't shrink the library right away

Optimize Mac Storage doesn't act the moment you turn it on. Apple describes it as keeping smaller versions when storage space is limited. While your Mac has room to spare, the full-size files stay, and the library can look as large as before.

When your Mac does need more space, Apple says iCloud Photos optimizes the library starting with the photos and videos you access least. Recently opened files and the optimized versions of your photos always stay on your Mac, so the library never shrinks to zero.

How do you check that iCloud Photos is really on?

There are two places to look, and both matter. In System Settings, click your name at the top of the sidebar, click iCloud, click Photos under Saved to iCloud, and check that Sync this Mac is on. Then, in Photos, check the iCloud pane of Photos › Settings, where the storage choice lives.

If the library is still uploading, the full-size originals have to stay until iCloud has them. In Photos, click Library in the sidebar, then All Photos, and scroll to the bottom to see the upload status.

Why only one library can use iCloud Photos

iCloud Photos syncs only your System Photo Library. Any other library, on this Mac or on a drive, keeps every original in full, because there's nowhere else for them to be. If a second library is large, Optimize Mac Storage won't touch it.

What does Optimize Mac Storage cost you?

Opening or editing an older photo needs an internet connection, and it may take a moment to download. Time Machine can back up only what's on your Mac, so a backup of an optimized library doesn't hold every original.

Apple's advice is to keep a backup copy of your library even with iCloud Photos, because photos aren't duplicated in your iCloud backup. If iCloud is your only copy, a mistaken delete reaches every device, and after 30 days it can't be undone.

Which fix fits your Mac?

The right first step depends on two things: whether you use iCloud Photos, and how your library compares with the space you have. Find your situation in the table, then read the section it points to.

Your situation	Best first step	What it costs
iCloud Photos on, Download Originals selected	Choose Optimize Mac Storage	Downloads when you open older photos
iCloud Photos on, already optimized, still large	Empty Recently Deleted, check uploads and other libraries	A few minutes
No iCloud Photos, library smaller than your iCloud plan	Turn on iCloud Photos, then Optimize Mac Storage	iCloud storage, and the first upload's time
No iCloud Photos, library larger than your plan	Move the library to an external drive	Photos needs the drive to open the library
Several libraries on the Mac	Open each, keep what's unique, back it up, then remove the rest	Time to check each one

A worked example

Say Storage settings shows Photos at 180 GB on a Mac with a 512 GB disk and 60 GB free, and Photos is set to Download Originals to this Mac. You switch to Optimize Mac Storage, and at first nothing seems to change. That's expected: with 60 GB free, macOS doesn't yet need the space.

Weeks later, a macOS update needs room. Photos now replaces the originals you open least with smaller versions, and the free space appears. Recent photos stay full size, so a trip you're still editing doesn't slow you down.

If you need the space today rather than when macOS decides, combine the switch with the steps below: empty Recently Deleted, merge duplicates and review videos. Those free space at once, because the items leave the library rather than waiting to be optimized.

What if your iCloud storage is full too?

Optimize Mac Storage can only let go of originals that are safely in iCloud, so it can't help much while uploads wait for room. Either buy more iCloud storage, or make room there by deleting photos and videos you don't want, which also frees space on the Mac.

If neither suits you, keeping the library on an external drive without iCloud Photos is the option that needs no subscription. Back the drive up as carefully as you would the Mac.

Delete what you don't need, in Photos

Deleting in Photos is the only safe way to remove items from the library. Photos keeps its database in step, and you get 30 days to change your mind.

The steps are the same in macOS 27 Golden Gate and macOS 26 Tahoe. On macOS versions before Ventura, Photos › Settings is called Photos › Preferences, and there's no Duplicates collection.

How do you delete photos and videos from the library?

1. Open Photos and select the items you want to remove. Hold Command to select several, or Shift to select a range.
2. Press the Delete key, then click Delete.
3. The items move to Recently Deleted, where they stay for 30 days.

Deleting from an ordinary album only removes items from that album; they stay in your library. Deleting from a smart album, such as Favorites or Videos, deletes them from the library.

Why didn't the space come back?

Because the items are still in Recently Deleted, and they keep their space there for 30 days. Click Recently Deleted below Utilities in the sidebar. If you don't see it, hold the pointer over Utilities and click the arrow that appears.

The album may be locked; click View Album and unlock it with Touch ID or your password. Then select items and click the Delete button, which shows how many you've selected, or click Delete All. Items deleted there are gone for good, unless a Time Machine backup still has them.

Start with the largest items

Click Videos below Media Types in the sidebar to see every video in one place. Long clips you'll never watch again, screen recordings and duplicated exports are often the quickest gigabytes to recover.

Bursts are worth a look too. Open Bursts below Media Types, double-click a burst, click Make a Selection, choose the shots you want, click Done, then Keep Only Selection. The rest go to Recently Deleted.

How do you merge duplicates?

Photos finds duplicates for you. Click Duplicates below Utilities in the sidebar; with a large library, they can take a while to appear. Select the duplicates you want to merge, or press Command-A for all of them, then click Merge and confirm.

One copy stays where the duplicates were, and the extra copies go to Recently Deleted. If you use iCloud Shared Photo Library, choose Both Libraries from the Library pop-up menu first, so duplicates across both show up.

Deleting with iCloud Photos on deletes everywhere

With iCloud Photos on, deleting a photo on your Mac deletes it on every device that uses the same library, and from iCloud. That's what you want for photos you don't need. It's not what you want if you're only trying to make room on the Mac.

To make room on this Mac without deleting anything anywhere, use Optimize Mac Storage, or move the library to an external drive.

Move the library to an external drive

If your library is larger than your iCloud plan, or you don't use iCloud Photos, an external drive is the cleanest way to take it off the internal disk. Apple documents the whole process, and it moves everything at once: originals, edits, albums and all.

How do you move the library?

1. Quit Photos.
2. In Finder, open the folder with your library; by default that's Pictures in your home folder.
3. Drag Photos Library to the external drive and wait for the copy to finish.
4. Double-click the library in its new place to open it in Photos.
5. If you use iCloud Photos, choose Photos › Settings, click General, and click Use as System Photo Library.
6. Check your photos, albums and edits are all there before you remove the original.

To free the space, drag the original library from Pictures to the Trash and empty the Trash. Do that only after the new copy has opened and you've looked through it.

Which drives can hold a Photos library?

Drive	Works for a library?	Why
External SSD or hard drive, APFS	Yes	Apple's recommended format
External drive, Mac OS Extended (Journaled)	Yes	Also supported
The drive you use for Time Machine	No	The library's permissions can conflict with the backup's
SD card or USB flash drive	No	Removable media risks data loss, Apple says
Network drive or cloud folder	No	Apple warns against both
A drive formatted for Windows, such as exFAT	No	Format it for Mac first

What happens if the drive isn't connected?

Keep the drive connected and turned on before you open Photos. If Photos can't find the library, it stops using it and creates a new, empty library in your Pictures folder. Your photos are still on the drive; quit Photos, connect it, and open the library again by holding Option as Photos opens.

If you get a permissions error when you drag the library, select the drive in Finder, choose File › Get Info, and select Ignore ownership on this volume under Sharing & Permissions. If that option is missing, the drive may not be formatted for Mac, or it was used for Time Machine without being erased.

What changes when you choose a new System Photo Library?

Choosing a different library as the System Photo Library turns off iCloud Photos and Shared Albums until you turn them on again in Photos' iCloud settings. When you do, Apple says the photos in iCloud merge with those in the new library, and everything from iCloud downloads to it.

For a library you've moved, this step is part of Apple's instructions, and the photos are the same ones. For a different library, the merge can't be undone, so be sure before you choose it.

Keep older photos in a second library

Some people keep the photos of past years in a separate library on an external drive, and only recent ones on the Mac. It works, with trade-offs worth knowing first.

How does a second library work?

Quit Photos, hold Option as you open it, and click Create New. Name the library, choose a place on the external drive, and click OK. To move between libraries, quit Photos and hold Option as you open it again.

To bring photos across, open the library you want them in, choose File › Import, select the other library, and click Review for Import. Then click Import All New Items, or select some and click Import Selected.

What does a second library cost you?

• Only the System Photo Library syncs with iCloud Photos, so a second library stays on its drive and nowhere else.
• Changes you make in a second library never reach iCloud.
• Apple advises backing up every library you make. A library on an external drive needs that drive in your backups, or a copy somewhere else.
• With iCloud Photos on, deleting the archived photos from your main library deletes them from iCloud and every device too.

That last point decides it for most people who use iCloud Photos. If you want older photos to stay on your iPhone, Optimize Mac Storage is the better tool. A second library suits people who don't use iCloud Photos, or who want older years off every device.

Should you export instead?

Exporting gives you plain files rather than a library. File › Export › Export Unmodified Original saves each item exactly as imported; a Live Photo becomes two files, a still and a video. File › Export › Export Photos saves a copy with your edits, in a format and size you choose.

Way out of the library	What you get	Edits kept?	Albums kept?
Move the whole library	The same library, somewhere else	Yes	Yes
Export Unmodified Original	The original files	No	No
Export Photos	Edited copies in a format you choose	Yes, applied	No

Exported files are fine as an archive, but they're a copy, not a library. Photos' albums, people and keywords stay behind.

Store imports outside the library

Photos can leave imported files where they are and point to them, instead of copying them into the library. Apple calls these referenced files. It's useful if you keep a large folder of photos on an external drive and want to browse them in Photos.

How do you turn copying off?

In Photos, choose Photos › Settings, click General, and deselect Copy items to the Photos library. From then on, imports stay in their original place. To find one later, select it and choose File › Show Referenced File in Finder.

What are the catches with referenced files?

• Referenced files aren't uploaded to iCloud Photos, so your other devices never see them.
• If you rename or move them in Finder, or disconnect their drive, Photos can't find them.
• Backing up the library doesn't back them up; you have to back them up yourself.

If you change your mind, select the items and choose File › Consolidate, then click Copy. Photos copies them into the library, where they're backed up and, with iCloud Photos on, uploaded.

What not to do with the Photos library

The Photos library looks like an easy target: one huge item, in a folder you can see. Most of the ways to lose photos start with treating it like an ordinary folder.

Don't	Why	Instead
Delete or move files inside the library in Finder	Photos tracks every file in its database, and can lose items or the whole library	Delete items in Photos
Trash the library because "it's all in iCloud"	Items that haven't finished uploading exist only here	Optimize Mac Storage, then check the upload status
Choose Turn Off and Delete from iCloud to save Mac space	Apple deletes the iCloud copy 30 days later	Choose Optimize Mac Storage
Keep a Time Machine backup on the drive that holds the library	Their permissions can conflict	Use separate drives
Trash an old library before checking it	It may hold photos your current library doesn't	Open it in Photos and import what's missing

Can you delete the Photos library if you use iCloud Photos?

It's the wrong tool. You'd need to be sure every item had finished uploading, and you'd lose the copy on your Mac that Time Machine backs up. Optimize Mac Storage gets you most of the same space back, keeps the albums and edits on your Mac, and doesn't depend on you being sure.

What if the library seems damaged?

If photos are missing or Photos behaves oddly, back up the library first, then repair it. Quit Photos, hold Option and Command, and click Photos in the Dock or in the Applications folder. In the Repair Library window, click Repair. If problems persist, restore the library from a Time Machine backup.

What happens when you turn off iCloud Photos on one Mac?

In Photos' iCloud settings, deselect iCloud Photos. Photos asks whether to Download everything from iCloud to this Mac, or Remove from Mac the items that aren't fully downloaded. The library stays in iCloud and on your other devices either way. Downloading everything is the opposite of saving space, so choose with care.

Other places your photos take up space

Photos isn't the only app that keeps pictures. If the Photos category is small but your disk is still full of images and video, look here.

Messages attachments

Every photo and video in your conversations is kept by Messages, separately from Photos, in ~/Library/Messages/Attachments. Saving one to Photos makes a second copy. Remove attachments in Messages itself, never in that folder. The post on Messages taking up space goes through every way to trim them.

Downloads, AirDrop and screen recordings

Photos and videos you AirDrop to your Mac, save from a website or record with the Screenshot app land as ordinary files, usually in the Downloads folder or on the Desktop. Storage settings counts them under Documents. Click the information button next to Documents to list your largest files.

Other photo and video apps

• Lightroom Classic keeps a preview file next to each catalog, in Pictures by default; it can be rebuilt, at the cost of slower browsing while Lightroom renders again. See Lightroom Classic previews.
• iMovie keeps imported clips and render files in its own library in your Movies folder. Delete render files in iMovie's settings, never in Finder.
• Cloud storage apps, such as Dropbox or Google Drive, keep copies of the photos you've opened or kept offline in their own folders. Use the app's option to remove the download, not Delete.

• Photos library10–500 GB · Managed by macOS
• Messages attachments5–100 GB · Review first
• Downloads and large old files5–100 GB · Review first

Typical ranges on Macs that have these items at all, from the research behind the app's catalog. Many libraries are far smaller, and the range depends mostly on video.

Keep the library from filling up again

A Photos library only grows unless you prune it, because with iCloud Photos every photo you take on your iPhone arrives by itself. A few habits keep it in proportion.

1. Choose Optimize Mac Storage once, if you use iCloud Photos, and leave it on.
2. After a trip or an event, delete the misses and keep the best of each burst.
3. Every month or two, check Duplicates and empty Recently Deleted.
4. Look at Videos below Media Types for long clips you don't need.
5. Open Photos with the Option key now and then, to check no forgotten library is growing.
6. Keep a backup of the library that isn't iCloud: Time Machine or a copy on a drive.

How much space should Photos take?

There's no right size. Without iCloud Photos, the library is as large as your collection. With Optimize Mac Storage, it settles somewhere smaller that depends on how full your disk is and which photos you open; Apple doesn't publish a figure.

What matters is whether it leaves room for the rest. If Photos alone fills more of the disk than you can spare, an external drive or a larger iCloud plan is the answer, not deleting photos you want. The guide to freeing up space on a Mac covers everything else that competes for the room.

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. File names and paths never leave your Mac.

On the map, the Photos library is one item with its real size, explained from the catalog's Photos library entry: what's inside, why you should change it only in Photos, and what Optimize Mac Storage and an external drive do. The same goes for every Photos library in your home folder, including ones you'd forgotten.

The library is Managed by macOS. The app never moves it or anything inside it; it tells you how to make it smaller with Photos' own settings. Messages attachments are Review first: explained, and left for you to remove in Messages. Large old videos elsewhere are Review first too, and nothing among them starts checked.

• ~/**/*.photoslibrary

  Photos library

  A Photos library: your photos and videos, your edits and albums, and the previews Photos makes from them.

  Managed by macOS · Explained only: the app shows you how

• ~/Library/Messages/Attachments

  Messages attachments

  Photos, videos, audio messages and files sent and received in Messages on this Mac.

  Review first · Explained only: the app shows you how

• ~/**/*

  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

The scan, the map, the explanations, System Data explained and Apple Data are free. Cleanup and the Apple Data actions, such as removing large old files after you review them, 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.