The short answer
No. Your data. Shrink it from its app; don’t delete the folder.
What is it?
Photos, videos, voice messages, stickers and files from your iMessage and SMS conversations, in ~/Library/Messages/Attachments. After years of conversations it commonly reaches tens of GB.
Photos, videos and files from your conversations. Review the largest ones in macOS storage settings; never deleted by MoreRoom.
What happens if you delete it?
Attachments deleted from Messages do not come back. With Messages in iCloud on, copies are also kept in iCloud, and macOS can keep older attachments only in iCloud when space is low.
How to remove it properly
Never delete files in this folder in Finder; it breaks the conversations that point to them. Open System Settings › General › Storage and click the info button next to Messages to review and delete large attachments, or set Messages › Settings › General › Keep messages to 1 Year or 30 Days.
From the app itself: System Settings > General > Storage > Messages: review large attachments.
Before you delete it
With Messages in iCloud, deleting an attachment or shortening Keep messages removes it from all your devices, permanently.
How MoreRoom helps
MoreRoom recognises this as your data and never suggests deleting it. It shows how much space it takes, so you can shrink it from its own app.
Frequently asked questions
Can I delete Messages attachments on my Mac?
No. Your data. Shrink it from its app; don’t delete the folder. Attachments deleted from Messages do not come back. With Messages in iCloud on, copies are also kept in iCloud, and macOS can keep older attachments only in iCloud when space is low.
Will Messages attachments come back after I delete it?
No. Attachments deleted from Messages do not come back. With Messages in iCloud on, copies are also kept in iCloud, and macOS can keep older attachments only in iCloud when space is low.
How do I remove Messages attachments properly?
Never delete files in this folder in Finder; it breaks the conversations that point to them. Open System Settings › General › Storage and click the info button next to Messages to review and delete large attachments, or set Messages › Settings › General › Keep messages to 1 Year or 30 Days.