How to Reduce Your Photos Library Size on a Mac

In short: Years of photos and 4K video can quietly claim tens of gigabytes on your Mac. Here's how to reduce your Photos library size using built-in tools like Optimize Mac Storage and the Duplicates album. Every step is safe, reversible, and free.

The Photos library is often the single largest folder on a Mac. A few years of Live Photos, screen recordings, and 4K clips can quietly grow past 100 GB. The good news: you can reclaim a lot of that space with tools Apple already built in, and you can do it without risking a single memory. This guide walks through the safe ways to reduce your Photos library size on a Mac running macOS Sonoma or Sequoia (14–15).

Find out how big your library actually is

Before you change anything, measure. Open a new Finder window, go to your Pictures folder, and look for Photos Library.photoslibrary. Right-click it and choose Get Info to see its size. This is your baseline, so jot it down.

It also helps to see the whole picture. Open the Apple menu, choose System Settings, then General, then Storage. The bar chart and the Photos row there tell you how much space photos and videos are using across the system, including any iCloud-synced originals stored locally.

Turn on Optimize Mac Storage

If you use iCloud Photos, the easiest win is letting macOS keep full-resolution originals in iCloud while storing smaller, device-sized versions on your Mac. Your originals stay safe in the cloud and download on demand when you need them.

Open the Photos app, go to Photos in the menu bar, choose Settings, then click the iCloud tab. Make sure iCloud Photos is on, then select Optimize Mac Storage instead of Download Originals to this Mac. macOS will gradually free space as it moves full-size files to iCloud. Nothing is deleted; the originals remain available and re-download whenever you open or export them.

One honest caveat: this only helps if you have enough iCloud storage for your full library. If you are on the free 5 GB tier and your library is 80 GB, Optimize Mac Storage cannot do much until you either upsize iCloud or trim the library itself.

Use the Duplicates album to merge copies

Since macOS Ventura, Photos automatically finds duplicate and near-duplicate images and gathers them in one place. It is one of the most effective ways to shrink a bloated library because merged copies are combined into a single item that keeps the highest quality version and all your keywords.

In Photos, look in the sidebar under Utilities for the Duplicates album. If you do not see it, the app is still scanning; give it time on a large library. Inside, you can review each set and click Merge on individual pairs, or select several and use Merge at the top. Photos keeps one clean copy and moves the redundant ones to Recently Deleted, so the change is easy to undo.

Clear Recently Deleted and old imports

Deleting photos in the app does not immediately free space. Removed items sit in the Recently Deleted album for up to 30 days. To reclaim that space now, open Recently Deleted in the sidebar (you may be asked to authenticate with Touch ID or your password), review the contents, and choose Delete All. Look here after merging duplicates or clearing out old screenshots and screen recordings, which are frequent space hogs.

Keep it safe and reversible

A quick reminder before you clean anything: work in a way you can undo. The Photos Duplicates and delete flows route items through Recently Deleted first, giving you a 30-day safety net. When you tidy files outside Photos, drag them to the Trash rather than permanently erasing them, so a wrong move is a quick restore, not a lost photo. Never dig into files inside the System folder to save space; that is not where your photos live, and it can break macOS.

If you want a cleaner for the rest of the Mac

Photos is only part of your storage story. Caches, old installers, and app leftovers add up elsewhere. A good cleaner should preview everything first, touch only user-level junk by default, and send removals to the Trash so they stay reversible. It also has no reason to phone home; if you are curious, a firewall like Little Snitch lets you confirm a tool stays quiet.

If you want a specific pick, CoreSweep is our top free choice: free forever, an optional one-time Pro at $49, zero telemetry, and reversible deletes. For a strong best-value runner-up, SkoonMac is free with a one-time $19 Pro. Either pairs well with the Photos steps above.

Put together, Optimize Mac Storage, the Duplicates album, and a quick pass through Recently Deleted will usually reclaim a meaningful chunk of your drive, safely and for free. Measure again with Get Info afterward, and you should see the difference.

Frequently asked questions

Does Optimize Mac Storage delete my original photos?

No. Optimize Mac Storage keeps your full-resolution originals safely in iCloud and stores smaller, device-sized versions on your Mac. Nothing is deleted, and originals re-download on demand whenever you open or export them. It only helps if you have enough iCloud storage for your full library.

Why doesn't deleting photos free up space on my Mac right away?

Removed items sit in the Recently Deleted album for up to 30 days before macOS actually reclaims the space. To free it now, open Recently Deleted in the Photos sidebar, authenticate if asked, and choose Delete All. That 30-day window is also your safety net if you change your mind.

Is it safe to merge duplicates in the Photos app?

Yes. When you merge duplicates, Photos keeps one copy at the highest quality along with all your keywords, and moves the redundant items to Recently Deleted rather than erasing them. Because merged copies pass through Recently Deleted first, the change is easy to undo for 30 days.

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