Storage Types

How to Clear Photos Library Cache on Mac

June 7, 2026·2 min read

Understanding Photos Library Storage

The Photos app on Mac maintains a library that includes your actual photos, edited versions, thumbnails, and analysis data used for face recognition and search. Over time, this cache data can grow significantly beyond the size of your actual photos. Clearing it is a useful way to clear storage on mac without deleting your pictures.

The Photos library is stored as a single package file in your Pictures folder by default.

Enable iCloud Photo Optimization

The most effective way to reduce photos app storage mac usage is to enable **Optimize Mac Storage** in Photos settings. Open Photos, go to **Photos > Settings > iCloud**, and check "Optimize Mac Storage." This keeps full-resolution photos in iCloud and stores only smaller versions locally.

This single setting can free up tens of gigabytes, especially if you have a large photo library. Your photos remain accessible — full versions download automatically when you open them.

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Clear the Photos Cache

Photos stores face recognition data, scene analysis, and thumbnail caches that can grow to several gigabytes. To clear this cache safely, quit Photos completely. Navigate to your Photos Library in Finder (usually in `~/Pictures`), right-click it, and look at its size with **Get Info**.

The cache files are inside the library package, and Photos will rebuild them as needed. One way to force a cache rebuild is to repair the library by holding **Option+Cmd** while opening Photos and clicking **Repair**.

Remove Duplicate Photos

Duplicate photos waste storage space. In macOS Ventura and later, Photos has a built-in **Duplicates** album that identifies matching photos. Open it, review the duplicates, and merge them to keep only one copy. This can save significant space depending on how many duplicates exist.

Delete Unwanted Photos and Videos

Review your library for screenshots, blurry photos, and videos you no longer need. Videos are especially large — a single minute of 4K video takes about 400 MB. Deleting a handful of old videos is often the fastest way to how to clear storage on mac through Photos cleanup.

Remember to check the Recently Deleted album in Photos and empty it. Deleted photos sit there for 30 days, still consuming space.

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Frequently Asked Questions

Will clearing Photos cache delete my pictures?

No. Clearing cache only removes temporary data like thumbnails and analysis files. Your actual photos and videos remain untouched.

How much space does Optimize Mac Storage save?

It depends on your library size. A 100 GB photo library might shrink to 5-10 GB locally while keeping everything accessible via iCloud.

Can I move my Photos library to an external drive?

Yes. Quit Photos, move the library file to your external drive, then open Photos while holding Option and select the new location.