macOS includes built-in storage recommendations that can help you reclaim space without manually searching through every folder. The most useful option is Optimize Storage, which removes watched movies and TV shows after you finish them and keeps only recent email attachments on your Mac when space is needed. Your original content remains available through the relevant Apple service, such as Apple TV or Mail, rather than being permanently erased.
Quick Answer
To use Optimize Storage on a Mac:
- Open the Apple menu and choose System Settings.
- Select General, then Storage.
- Review the recommendations under Recommendations.
- Select Optimize next to Optimize Storage.
- Read the explanation and confirm your choice.
Depending on your Mac and macOS configuration, you may also see recommendations to store files in iCloud, automatically empty the Trash, or review large and unused files. These options make different changes, so check each description before enabling it.
What Optimize Storage Actually Does
The name Optimize Storage can be confusing because it does not optimize every file on your Mac. It is a specific macOS recommendation designed mainly for content downloaded from Apple services.
When enabled, macOS can:
- Automatically remove watched movies and TV shows from your Mac when storage space is needed.
- Keep only recent email attachments on your Mac when space is limited.
- Allow you to download the removed content again later when you have an internet connection.
The option does not generally compress your personal files, delete random documents, or move your entire Mac library to the cloud. It also does not automatically remove every application or unused file.
What remains in iCloud or online
Optimize Storage is separate from iCloud storage recommendations. If you use Optimize Mac Storage with iCloud Drive, macOS may remove the local copy of an iCloud Drive file when your Mac needs space. The file remains in iCloud and can be downloaded again.
Similarly, removing a watched movie or TV show from your Mac does not necessarily mean it is gone from your Apple account. Purchased or otherwise available content can generally be downloaded again through the service where you obtained it.
Email attachments work differently. Optimize Storage may remove older local attachment downloads while the messages themselves remain available through your email account. Whether an attachment can be downloaded again depends on your email provider and account settings.
Always distinguish between:
- Removing a local copy: The item is no longer stored on your Mac but remains available online.
- Deleting an item: The item may be removed from the service, account, or Trash and may not be recoverable.
- Using iCloud: A copy is stored in iCloud, which uses your iCloud storage allowance.
Before You Enable Storage Recommendations
Before changing storage settings, consider these limitations:
- You need an internet connection to download content again after a local copy is removed.
- Streaming services may require an active subscription or account access.
- Files stored only in iCloud may not be available when you are offline.
- iCloud storage is separate from your Mac’s internal storage. Moving files to iCloud does not eliminate the need for adequate iCloud capacity.
- Optimize Storage does not replace a backup. Use Time Machine or another backup system for important files.
- If an app is open and you are about to delete or move files manually, save your work first.
The recommendations are most useful when your Mac is running low on space and you want macOS to manage certain kinds of content automatically.
How to Turn On Optimize Storage
Follow these steps to enable the specific Optimize Storage recommendation.
- Click the Apple menu in the upper-left corner of the screen.
- Choose System Settings.
- In the sidebar, click General.
- Select Storage.
- Wait for macOS to calculate your storage use.
- Find the Recommendations section.
- Locate Optimize Storage and click Optimize.
- Read the confirmation message, then confirm that you want to enable the recommendation.
The setting may not appear if your Mac does not currently support the recommendation, if there is not enough applicable content to manage, or if storage information has not finished loading.
Enabling the option usually does not immediately delete everything it can manage. macOS applies the recommendation as needed, particularly when available storage becomes low.
Other macOS Storage Recommendations
The Storage settings may show several recommendations. Each one affects your Mac differently.
Store in iCloud
The Store in iCloud recommendation can store files, photos, and other supported content in iCloud to reduce the amount of data kept locally on your Mac. The exact categories available may depend on your iCloud settings.
When a file is stored in iCloud but removed from the Mac, you may see a download icon beside it in Finder. Opening the file downloads it again. This saves local space but requires an internet connection and available iCloud storage.
To use it:
- Open System Settings.
- Select General, then Storage.
- Find Store in iCloud.
- Click Store in iCloud or its associated button.
- Review the categories and confirm only the ones you want to use.
Do not enable this option without checking your iCloud storage. If iCloud is full, files may not upload successfully, and you may not receive the expected space savings.
Empty Trash Automatically
This recommendation can automatically remove items that have remained in the Trash for a set period. Once the Trash is emptied, recovering those files becomes more difficult and may require specialized recovery software.
Before enabling it:
- Open the Trash from the Dock.
- Review its contents.
- Restore anything you may need.
- Empty the Trash manually only after confirming the files are no longer needed.
To enable the recommendation, open System Settings > General > Storage, locate Empty Trash Automatically, and select its button if it is available.
Warning: Emptying the Trash permanently removes the items from their normal recovery location. Save any files you want to keep before turning on automatic emptying.
Reduce Clutter
The Reduce Clutter area helps you review items that may be taking up significant space, such as large files, downloads, unsupported apps, or files that have not been opened recently.
Use it as a review tool rather than a command to delete everything:
- Open System Settings > General > Storage.
- Select Reduce Clutter or a related review option.
- Choose a category.
- Sort or inspect the listed items.
- Select only files you recognize and no longer need.
- Click the delete button and confirm.
For a more targeted manual review, see this guide to finding large files on a Mac.
Warning: Deleting a file from Storage settings may remove it immediately or move it to the Trash, depending on the item and macOS behavior. Do not delete system files, application support files, or personal documents unless you understand what they contain.
How to Check Whether You Freed Space
After using a recommendation, return to System Settings > General > Storage and allow the storage categories to recalculate. The total may not change immediately because macOS needs time to update its storage report.
You can also check available space in Finder:
- Open a Finder window.
- Click your Mac’s internal drive in the Finder sidebar, if it is shown.
- Choose File > Get Info.
- Review the Available amount.
The Storage panel is usually more useful because it groups data into categories such as Applications, Documents, Photos, Mail, macOS, and System Data. These categories may change as macOS reindexes files or clears temporary data.
How to Turn Off Optimize Storage
If you prefer to manage downloads yourself, you can disable the recommendation.
- Open System Settings.
- Select General.
- Click Storage.
- Find Optimize Storage under Recommendations.
- Click the control associated with the setting and turn it off, if available.
Turning off Optimize Storage does not automatically restore movies, TV shows, or email attachments that were previously removed from the Mac. You must download those items manually through the appropriate app or service.
If your goal is to keep all media available offline, download the content again while you have enough free space. If you want to keep local copies of email attachments, open the relevant messages and save the attachments to a folder on your Mac.
What to Do If Optimize Storage Does Not Free Enough Space
Optimize Storage manages only certain types of data. If your Mac remains nearly full, inspect other categories instead of repeatedly enabling the same recommendation.
Check these areas:
- Applications: Remove apps you no longer use.
- Documents: Review old projects, installers, videos, and disk images.
- Downloads: Delete duplicate installers and files you have already moved elsewhere.
- Photos: Review large libraries and verify that your photo backup is complete before deleting anything.
- Mail: Remove unnecessary messages with large attachments if they are no longer needed.
- iPhone and iPad backups: Delete old device backups only after confirming you do not need them.
- System Data: Restart your Mac and allow temporary files and caches to be recalculated before attempting advanced cleanup.
For a broader, step-by-step cleanup, use this guide to free up storage space on a Mac.
Do not delete System Data manually
System Data can include caches, logs, virtual memory, local snapshots, app support files, and other items macOS manages. Its size may fluctuate, and the category is not a single folder that can safely be emptied.
Avoid deleting unknown files from system folders to reclaim space. Doing so can cause apps or macOS features to malfunction. Start with personal files, unused apps, old downloads, and content that you can replace.
Troubleshooting Optimize Storage
The Optimize Storage option is missing
Make sure you are viewing System Settings > General > Storage and wait for the storage summary to finish loading. The recommendation may be unavailable if macOS has no applicable content to manage or if your Mac has not identified a storage need.
The storage number has not changed
Storage calculations can take time. Close unnecessary apps, restart your Mac, and check the Storage panel again. If you enabled iCloud-related options, verify that files have finished uploading before expecting local space to be released.
A movie or TV show was removed
Look in the Apple TV app or the service where you obtained the content. If it is still available to your account, download it again for offline viewing. You need sufficient free space and an internet connection.
An email attachment is no longer stored locally
Open the original message in Mail and try downloading the attachment again. If the message is unavailable, check your email provider’s webmail service. Do not delete the message until you have confirmed that you no longer need the attachment.
iCloud storage is full
Open System Settings, click your name, and select iCloud to review your iCloud usage. You may need to delete unnecessary iCloud data, change what syncs, or upgrade your iCloud plan. Do not remove iCloud files without checking whether other devices or people rely on them.
You need more free space immediately
Start with large personal files, old downloads, unused applications, and media you can redownload. Empty the Trash only after reviewing it carefully. If you need to remove files from the Mac but keep them elsewhere, copy them to a verified external drive before deleting the originals.
Frequently Asked Questions
Does Optimize Storage delete my files permanently?
Usually, it removes local copies of supported content rather than deleting the content from your account. Movies, TV shows, and some email attachments may be downloaded again. However, you should verify where the original remains before relying on this behavior.
Does Optimize Storage use iCloud?
The Optimize Storage recommendation itself is mainly associated with Apple TV downloads and Mail attachments. The separate Store in iCloud recommendation uses iCloud to keep supported files online and reduce local storage use.
Can I choose which movies macOS removes?
Optimize Storage is an automatic recommendation, so it may not provide detailed per-item controls. If you need specific movies or shows available offline, download them again or manage downloads directly in the Apple TV app.
Will Optimize Storage delete my Photos library?
Optimize Storage does not automatically delete your Photos library. Photo storage is managed through Photos and iCloud Photos settings, including the option to optimize Mac storage for photos when iCloud Photos is enabled.
Does Optimize Storage improve Mac performance?
It can help prevent problems caused by extremely low free space, but it is primarily a storage-management feature. It does not upgrade hardware or make every Mac faster.
Should I enable every storage recommendation?
No. Review each recommendation separately. Automatic Trash emptying and iCloud storage can affect how you access or recover files, so enable only options that fit your backup and offline-access needs.
Final Thoughts
Optimize Storage is a convenient way to let macOS remove replaceable local content when space is needed. It does not clean every part of your Mac, and it does not replace backups. Check what each recommendation changes, confirm that important files remain backed up or available online, and use manual cleanup for large files and apps that macOS does not manage automatically.