I recently got an M4 Mac Mini and ran migration assistant to move everything from the M2 Mini being replaced. In getting a new machine I has downsized from 512 GB to 256 GB SSD.
A month into the new machine, via iStat Menus, I received a message telling my hard drive was nearly full. This took me by surprise. I ran the M2 with about 180 gb of data on it and I expected the new M4 would be the same. But no, the data on the SSD had grown past 200 GB.
I ran Clean My Mac and went beyond the usual scan that finds 4gb of data. I used a feature called Space Lens which examines the SSD and looks for large files and folders. I was surprised at what it found.
I’d group its findings into three buckets:
- Temp files. For example, inside in Text Edit, there was an 8 GB TMP folder and file.
- Universal binaries. In plain English, these are files in apps that enable them to work on the old Intel chip Macs. The files aren’t needed to run on the M-Series Apple silicon chips.
- AI application temp files. On my M5 MacBook Pro, I found Claude had some files sitting at 17 GB.
Before deleting files, I checked with Gemini on what was safe to remove and the guidance it provided was pretty solid.
On my two Macs, I reclaimed about 30 to 40 GB of storage on each and have set up a quarterly reminder to run Space Lens to keep an eye on folders.
18 October 2026