How to Manage Photos Storage on Mac

How the Photos Library Works on macOS

The Photos app stores everything inside a single package file called Photos Library, located by default at ~/Pictures/Photos Library.photoslibrary. It looks like one item in Finder, but it is actually a bundle containing all your originals, edited versions, thumbnails, and a database that tracks albums, faces, and metadata. Every photo you take, import, or receive lives inside this package. On a Mac used for several years, it commonly reaches 100 GB or more — and for keen photographers or people who shoot a lot of video, it can pass 500 GB.

The key thing to understand is iCloud Photos. If you enable it under Photos > Settings > iCloud, your entire library syncs to Apple's servers, and you get a choice of two modes. Download Originals to this Mac keeps full-resolution copies of everything locally — great for a backup, but heavy on storage. Optimize Mac Storage keeps full-resolution originals in iCloud and stores smaller, space-saving versions locally, downloading the full file only when you need it. This single setting is the most powerful lever you have over how much space Photos uses.

How to Check How Much Space Photos Is Using

Before you change anything, confirm how big the problem is. There are two easy ways to see the real number.

• Storage settings: Open System Settings > General > Storage. The Photos entry shows how much local space the library occupies. Click the "i" button beside it for a breakdown and recommendations.
• Finder: Go to ~/Pictures, select Photos Library.photoslibrary, and press Command + I. The Get Info panel shows the total size of the package on disk.

If the number is far larger than you expected, the usual causes are that you have "Download Originals" enabled, you shoot in high-resolution formats, or you have a large volume of videos — which take vastly more space than stills.

Turn On Optimize Mac Storage

If you use iCloud Photos, enabling Optimize Mac Storage is the fastest way to reclaim a large amount of space with zero risk of losing photos. macOS keeps the full-resolution originals in iCloud and replaces local copies with smaller versions, freeing space automatically as needed.

1. 1
   Open Photos and go to Settings. Launch the Photos app, then choose Photos > Settings from the menu bar (or press Command + Comma).
2. 2
   Open the iCloud tab. Confirm that iCloud Photos is turned on. If it is not, enabling it will begin uploading your library to iCloud.
3. 3
   Select "Optimize Mac Storage." Choose this option instead of "Download Originals to this Mac." macOS will start replacing local full-resolution files with space-saving versions.
4. 4
   Give it time. The library shrinks gradually as macOS offloads originals, prioritising older and less-used photos. The more free space your Mac needs, the more it offloads.

Delete Photos, Videos, and Duplicates You Do Not Need

Optimizing local storage helps, but the surest way to shrink the library permanently is to remove content you genuinely do not want. A few targets deliver the biggest wins:

Large videos. Video is the heaviest content in any library. In Photos, use the sidebar to open Media Types > Videos, review them, and delete the ones you no longer need. A handful of 4K clips can free several gigabytes on their own.

Screenshots and screen recordings. Under Media Types > Screenshots, you will often find hundreds of throwaway captures. These rarely have sentimental value and are safe to clear in bulk.

Duplicates. Recent versions of Photos include a built-in Duplicates album in the sidebar that detects exact and near-duplicate images and offers to merge them, keeping the highest-quality version. Merging duplicates can recover meaningful space with no risk.

Deleting from Photos is not instant. Removed items go to the Recently Deleted album (found in the sidebar) and stay there for up to 30 days before being purged. To reclaim the space immediately, open Recently Deleted and choose Delete All.

Find Photo Bloat Faster with TrimyMac

Reviewing thousands of photos by hand is slow, and Photos does not surface where the biggest space savings hide. TrimyMac helps you understand what your Photos library and the rest of your disk are really holding. Its storage analysis reveals the size of your Photos Library package and other large media, and Smart Clean clears the caches, thumbnails, and leftover temporary files that photo workflows leave behind across your Mac — safely, and without touching your actual images.

1. 1
   Download and open TrimyMac. Install it from the link below and launch it from your Applications folder.
2. 2
   Run the storage analysis. See a clear breakdown of what is filling your disk, including the size of your Photos Library and other large media folders.
3. 3
   Run Smart Clean. Clear photo-related caches, thumbnails, and temporary export files across your Mac in one pass, keeping every original image untouched.
4. 4
   Review and clean. Confirm what TrimyMac found and click Clean to reclaim the space. A summary shows exactly how much you recovered.

Move the Photos Library to an External Drive

If you want to keep full-resolution originals but free up your internal drive, you can move the entire Photos Library package to an external SSD. Quit Photos, drag ~/Pictures/Photos Library.photoslibrary to the external drive, then double-click it there to open it in Photos. To make it the default, go to Photos > Settings > General and click Use as System Photo Library while that library is open.

This approach suits photographers who need every original on hand but do not want them eating internal storage. The trade-offs: the external drive must be connected to browse or edit, and it should be a fast, reliable SSD formatted as APFS. Always keep a separate backup of the library — moving it to a single external drive is not itself a backup, so pair it with Time Machine or iCloud.

Is It Safe to Manage Photos Storage This Way?

Yes, when you use the built-in tools as intended. Turning on Optimize Mac Storage is completely safe because your originals remain in iCloud — you are only changing which resolution is stored locally. Merging duplicates keeps the best version automatically. Deleting content is safe as long as you understand that items go to Recently Deleted first and are recoverable for 30 days.

The one rule to follow: never delete the Photos Library.photoslibrary package directly in Finder to "clean up," and never dig into its internal folders to remove files manually. Doing so can corrupt the library database and lose photos. Always manage content from inside the Photos app, and let a tool like TrimyMac handle only the safe caches and temporary files that live outside the library package.