How to Clear Messages Storage and Delete Old iPhone Backups on a Mac
Two of the biggest space users on a Mac are things most people never look at. Messages keeps every photo, video, GIF and voice note anyone has ever sent you, by default forever. And every time you back up an iPhone or iPad to your Mac, Finder stores a full copy that stays there long after the device is gone. Between them, it's common to find 30–100GB.
Quick answer: To shrink Messages, open Messages → Settings → General and change Keep messages from Forever to 1 Year or 30 Days, or review big attachments in System Settings → General → Storage → Messages ⓘ and delete them. If Messages in iCloud is on, deletions apply to all your devices. To delete old iPhone or iPad backups, open Finder, select a device, click Manage Backups, right-click a backup and choose Delete. Don't delete backup or Messages files directly in your Library folder. MacCove Space finds Messages attachments, old device backups and iPhone software files in a single scan.
Part 1: Messages
Where Messages stores its data
Messages keeps your conversation history in a database (~/Library/Messages/chat.db) and every photo, video and file in ~/Library/Messages/Attachments. Attachments are what make it big. A few years of group chats full of videos can easily reach 20GB or more.
Don't delete files inside the Attachments folder by hand. The database still points to them, so you end up with broken attachments, and if Messages in iCloud is on, it can get confused about what to sync. Use the methods below instead.
First, check whether Messages in iCloud is on
This changes what deleting does:
| Messages in iCloud | What deleting on your Mac does | Storage effect |
|---|---|---|
| On | Deletes the message or attachment from all your devices | Frees space on your Mac and in iCloud |
| Off | Deletes it from your Mac only | Frees space on your Mac only |
To check, open Messages → Settings → iMessage and look for Enable Messages in iCloud. If you want to keep everything on your iPhone but free space on the Mac, Messages in iCloud has to be off. Deleted messages go to Recently Deleted for up to 30 days before they're removed for good.
Option 1: Automatically delete old messages
Open Messages → Settings → General.
Change Keep messages from Forever to 1 Year or 30 Days.
Confirm. Messages deletes conversations and attachments older than that.
This is the most effective setting, but it's also blunt: it removes the text of old conversations as well as attachments. If you want to keep old conversations, use option 2.
Option 2: Delete only the large attachments
Open System Settings → General → Storage.
Click the ⓘ next to Messages.
Sort the attachments by size, select the big ones (videos usually top the list) and click Delete.
You can also do this within a conversation: click the contact's name at the top, scroll to the photos and attachments, select the ones you don't need and delete them.
Option 3: Delete whole conversations
Right-click a conversation in the sidebar and choose Delete, or swipe left on it with two fingers. Old group chats with lots of media are usually the best candidates.
Part 2: iPhone and iPad backups
Find your backups
When you back up an iPhone or iPad to your Mac (rather than iCloud), the backup is stored in ~/Library/Application Support/MobileSync/Backup. Each one is a full copy of the device's data and can be anywhere from a few gigabytes to over 100GB. Old backups are never deleted automatically, so backups from phones you sold years ago are often still there.
Delete old backups in Finder
Open Finder and select an iPhone or iPad in the sidebar. You need a device connected to see this screen, but you can manage backups for all devices from there, including ones you no longer have.
In the General tab, click Manage Backups.
Right-click a backup and choose Delete (or Show in Finder to see where it is).
Confirm.
If you have no device to connect, you can find the backup folders in ~/Library/Application Support/MobileSync/Backup. Each one is named with a long string of characters. Apple advises against editing, renaming or extracting files from backups, so delete a whole backup folder or nothing.
Before you delete a backup
| Check | Why |
|---|---|
| Do you have a more recent backup? | Keep at least one up-to-date backup per device you still use |
| Is iCloud Backup on for that device? | If so, a Mac backup may be redundant |
| Is it an archived backup? | Archived backups are snapshots you chose to keep, and aren't replaced by new backups |
| Is it encrypted? | Encrypted backups are the only local ones that include saved passwords, Health and Activity data |
Move backups instead of deleting them
If you want to keep old backups but not on your Mac's internal drive, copy the backup folder to an external drive and then delete it from the Mac. Some guides suggest moving the whole Backup folder and leaving a symbolic link behind so new backups go to the external drive. It works, but Apple doesn't support it and backups will fail whenever the drive isn't connected.
Don't forget iPhone software files
When you update or restore an iPhone or iPad through Finder, your Mac downloads the full iOS software file (.ipsw), often 5–10GB. These can sit in ~/Library/iTunes/iPhone Software Updates (and an iPad equivalent) long after they're needed. Delete them once the update is done.
Part 3: Time Machine backups and snapshots
If you use Time Machine, there are two more things that can look like they're using space:
Local snapshots on your Mac. macOS keeps hourly snapshots for about 24 hours and counts the space as available, deleting them when it needs room. If you want them gone now, turn off automatic backups in System Settings → General → Time Machine, wait a few minutes, and turn them back on.
Backups on your external drive. These don't take space on your Mac at all. Time Machine deletes the oldest ones automatically when the backup drive fills up.
Our guide on how to clear System Data has the Terminal commands for snapshots.
Finding all of it at once
Messages attachments, device backups and .ipsw files are spread across three different parts of your Library, none of which Finder shows by default. MacCove Space finds them in a single scan, shows the size of each, and lets you review them before anything is removed. It doesn't upload anything; scanning and cleaning happen entirely on your Mac.
FAQs
Why does Messages take up so much space on my Mac?
Because Messages keeps every attachment forever by default, and with Messages in iCloud it downloads your whole history to every device. Photos and videos in group chats are usually the bulk of it.
If I delete messages on my Mac, will they be deleted on my iPhone?
Only if Messages in iCloud is on. In that case, deletions sync across all your devices. If it's off, deleting on the Mac doesn't affect your iPhone.
Can I delete the Messages Attachments folder?
You shouldn't. Messages still references those files, so deleting the folder by hand leaves broken attachments. Delete attachments from within Messages or from Storage settings instead.
Is it safe to delete old iPhone backups on my Mac?
Yes, as long as you have a recent backup of any device you still use (or iCloud Backup is on). Backups of devices you no longer own are safe to delete.
Where are iPhone backups stored on a Mac?
In ~/Library/Application Support/MobileSync/Backup. The easiest way to manage them is Finder → your device → Manage Backups.
Related guides
How to Free Up Disk Space on a Mac
How to Clear System Data on a Mac
How to Find Large Files on a Mac