Photos Library Eating Your Storage? Here's How to Trim It

The Photos library is the single biggest folder on a typical Mac. Mine clocks in at 184GB. A friend’s hits 410GB. The library file (Photos Library.photoslibrary) sits in ~/Pictures and grows continuously as you take new photos and import old ones.

The thing is, you don’t have to delete photos to reclaim space. macOS has built-in mechanisms to keep your full library “available” while only storing thumbnails locally. Plus a few less-obvious tricks for cutting library size further. Here’s the full menu.

Step 1: The biggest single switch — Optimize Mac Storage

Open Photos → Settings (Cmd+,) → iCloud. There’s a radio button: “Download Originals to this Mac” vs. “Optimize Mac Storage.”

If “Download Originals” is selected and you have a big iCloud Photo Library, your entire library is local. Switch to “Optimize Mac Storage.” macOS keeps thumbnails locally and pulls full resolution from iCloud only when you open a photo.

For a typical user, this single change shrinks the local Photos library by 70-90%. A 200GB library can drop to 30GB on disk while still being fully accessible.

The catch: when offline, you only see thumbnails. The originals download on demand when you’re back online. For most people that’s fine. For someone editing photos on a flight, it’s a problem.

The change is gradual. Photos doesn’t immediately delete originals — it thins them over hours or days as it judges what you’re not actively viewing. Don’t panic if your library size doesn’t drop immediately.

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Step 2: Empty the Recently Deleted album

When you delete a photo, it goes to Recently Deleted and stays there for 30 days. Useful safety net. Also a quiet storage cost.

Photos → sidebar → Recently Deleted. Cmd+A to select all, click Delete All. Confirm.

You can also let it auto-purge by waiting 30 days, but if you’re tight on space right now, empty it manually.

Step 3: Use the Duplicates album

Since Ventura 13, Photos has a built-in Duplicates album (sidebar → Library → Duplicates). It scans your library using image hashing and groups duplicates together.

For each group, click “Merge X items.” Photos keeps the highest-quality version, deletes the rest, and combines metadata.

If your library has imported from multiple sources over the years (iCloud sync + manual imports + restores), expect 5-15GB of duplicates. The cleanup pays for itself.

Don’t forget to also empty Recently Deleted afterward — merged duplicates go there first.

Step 4: Find the giant videos

Videos are massive compared to photos. A 4K video at 30 minutes can be 8GB. A few of those, and your library is bloated regardless of photo count.

In Photos, sidebar → Media Types → Videos. View → Sort → Sort by Largest First isn’t a built-in option, unfortunately, so a workaround:

1. Sort by Date (View → Sort by Date)
2. Scroll through, looking for video thumbnails (they have a clock or timer icon)
3. Click each suspect, check the file size in the info pane (Cmd+I)

Or, faster: right-click the Photos library file in ~/Pictures → Show Package Contents → originals folder → sort by size. You can see which actual files are largest. Don’t delete them from there directly (Photos’ database will get confused), but use the filename to find and delete the photo from inside Photos.

The biggest video offenders are usually:

• 4K screen recordings
• Slow-motion clips (often 500MB-2GB each)
• Cinematic mode videos (iOS 15+)
• Live Photos from old phones (which include short videos)
• Videos AirDropped or sent over Messages that auto-saved

Step 5: Bursts are another size offender

When you take burst photos on iPhone (hold the shutter), it captures 10+ shots. Photos imports all of them. Most people only want one.

Sidebar → Media Types → Bursts. For each burst, click “Make a Selection,” choose the keepers, and Photos can delete the rest.

A heavy iPhone user with hundreds of bursts can free 5-10GB this way.

Step 6: Screenshots cleanup

Screenshots auto-save to Photos by default if you have iCloud Photo Library on. They tend to accumulate fast — meeting screenshots, web page captures, ephemeral stuff that doesn’t need to live forever.

Sidebar → Media Types → Screenshots. Browse, mass-select, delete the ones you don’t need.

If you want to stop screenshots from going to Photos in the first place: there’s no toggle for this, but you can route screenshots to a folder instead. Press Cmd+Shift+5 → Options → Save to → choose a custom folder. From then on, screenshots save to that folder, not auto-import to Photos.

Step 7: The hidden caches inside the library

The Photos library is technically a folder (a “package”) that contains thousands of files. Some of them are caches that bloat over time.

To check: quit Photos. Then in Finder, navigate to ~/Pictures/Photos Library.photoslibrary → right-click → Show Package Contents.

Folders inside that can grow large:

• caches/ — thumbnail caches and various preview data
• resources/derivatives/ — generated thumbnails for fast scrolling
• private/ — internal Photos working data

You can technically delete caches/ and resources/derivatives/, and Photos will rebuild them on next launch. The rebuild is slow — easily 30-60 minutes for a big library — but it can shrink the library by 5-15GB.

Don’t touch originals/, previews/, or database/. Those are your actual photos and metadata. Deleting any of them loses data permanently.

Reclaim 20+ gigs in one passSweep finds the caches, snapshots, and old downloads adding up to most of your “System Data.” Free download →

Step 8: Move the library to an external drive

If your library is just genuinely huge (500GB+) and trimming isn’t enough, move it off your boot drive.

1. Quit Photos
2. Plug in an external drive (SSD recommended for performance)
3. Drag ~/Pictures/Photos Library.photoslibrary to the external drive
4. Wait for the copy (slow for large libraries — easily an hour for 200GB)
5. Hold Option while launching Photos
6. Select the moved library file as your library
7. Verify it works
8. Delete the original from ~/Pictures once verified

Set this drive as your “System Photo Library” in Photos → Settings → General if you want iCloud Photo Library to sync to it.

The catches: the external drive needs to always be plugged in for Photos to work. If you’re on a laptop and unplug, Photos can’t open the library. So this is mostly a desktop strategy, or a “leave external attached when at home” strategy.

Step 9: Be selective about what gets imported

If you take a thousand photos a year, your library grows by tens of GB regardless of what you do. The most effective long-term strategy is being more selective:

• Don’t auto-import everything from old phone backups
• Decline to import RAW photos if you don’t process them (they’re 5-10x JPEG size)
• Disable Photo Stream for shared albums you’re not curating
• Delete dud photos at the moment you take them, not “someday”

This is a habit, not a feature. But it’s the only fix that scales over time.

What NOT to do

A few things you’ll see suggested elsewhere that aren’t actually safe:

• Don’t manually delete files from originals/ inside the library. Photos’ database doesn’t know they’re gone, and you’ll see broken thumbnails forever.
• Don’t delete database/photos.sqlite. It’s the index of your entire library. Without it, Photos has to re-scan everything from scratch.
• Don’t run “compact” or “optimize” tools designed for older iPhoto. They don’t work on the modern Photos format and can corrupt your library.
• Don’t trust YouTube tutorials about “secret Photos cleanup commands.” Anything involving direct manipulation of the library’s internals is risky.

The right tools for shrinking Photos are: Optimize Mac Storage, the Duplicates album, Recently Deleted, and being more selective about imports. Everything else is unnecessary risk.

Realistic expectations

For a typical user with a 200GB library:

• Optimize Mac Storage: drops local size to maybe 30GB
• Duplicates merge: another 5-10GB if you’ve never done it
• Cache cleanup: another 3-5GB
• Recently Deleted purge: 1-3GB

Total: from 200GB on disk to 35-45GB. That’s a real difference. And your full library is still accessible — just stored in iCloud rather than locally.

If you don’t use iCloud Photos, the savings are smaller and harder-won. You’d be looking at duplicate cleanup and selective deletion only, probably saving 10-30GB at most.

For most people, the answer to “Photos library too large” is just toggling Optimize Mac Storage. Five seconds, no risk, biggest single win available.