--- title: "Drive formats: APFS, Mac OS Extended and exFAT" url: https://storagestudio.us/wiki/drive-formats category: "External drives" tags: ["external drive", "glossary", "data parking"] summary: "APFS is the recommended format for a Storage Studio drive. Mac OS Extended also works, exFAT works with warnings, and FAT32 and network drives are refused." updated: 2026-10-01T05:34:20.000Z --- # Drive formats: APFS, Mac OS Extended and exFAT APFS is the recommended format for a Storage Studio drive. Mac OS Extended also works, exFAT works with warnings, and FAT32 and network drives are refused. A drive's **format** decides what it can store besides the files themselves — shortcuts, permissions, access lists and more. Storage Studio relies on those, so it checks the format of any drive you choose and tells you how well it fits. ## How each format is treated | Format | What Storage Studio says | Why | | --- | --- | --- | | APFS | Compatibility: looks good | The Mac's own modern format — holds everything a move keeps. Recommended. | | Mac OS Extended (Journaled) | Compatibility: looks good | The older Mac format; also holds what a move needs. | | exFAT | Compatibility: usable with warnings | Readable by Windows too, but can't hold several things Macs rely on. | | MS-DOS (FAT32) | Compatibility: not suitable | Can't hold shortcuts. | | A network drive | Compatibility: not suitable | Network drives aren't supported. | | Anything else | Compatibility: usable with warnings | Called non-standard; APFS or Mac OS Extended is recommended. | The checks appear when you select a drive in **Choose External Drive** — see [Setting up your drive](https://storagestudio.us/wiki/setting-up-your-drive). A drive marked **not suitable** can't be chosen; for one with warnings, the confirm button reads **Use Anyway**. For exFAT, the warning says the format has known issues with macOS shortcuts and permissions, and that APFS is strongly recommended. More in [What to know about exFAT drives](https://storagestudio.us/wiki/exfat-drives). ```mermaid %% caption: How the drive check treats each format flowchart LR A[Drive format] --> B{Which one?} B -->|APFS| G[Looks good - recommended] B -->|Mac OS Extended| G2[Looks good] B -->|exFAT| W[Usable with warnings] B -->|FAT32 or network| N[Not suitable] ``` *Flowchart — How the drive check treats each format. Outline:* - Drive format - leads to Which one? - Which one? - APFS: leads to Looks good - recommended - Mac OS Extended: leads to Looks good - exFAT: leads to Usable with warnings - FAT32 or network: leads to Not suitable ## Case-sensitive formats APFS and Mac OS Extended both come in a **case-sensitive** version, where "Photo.jpg" and "photo.jpg" can be two different files. Your Mac's own disk is normally not case-sensitive, where those two names are the same file. That difference matters when things move back and forth. Before moving an app, the [Apps window](https://storagestudio.us/wiki/the-apps-window) checks how both your Mac and the drive treat capital letters. If the app contains files whose names differ only in capitals, or if it can't tell how a drive behaves, it refuses the move rather than risk losing a file. Unless you need a case-sensitive drive for a particular reason, the standard, not case-sensitive APFS is the simplest choice. ## Changing a drive's format Formatting is done in macOS's **Disk Utility** with **Erase**, and it **erases everything on the drive**. Copy anything you want to keep somewhere else first. If the drive already holds folders or apps that Storage Studio moved, bring them back to your Mac first — see [Moving a folder back](https://storagestudio.us/wiki/moving-a-folder-back) — or move them to another drive with [Transfer to a New Drive](https://storagestudio.us/wiki/transfer-drive-and-backup-drive). See also: [APFS](https://storagestudio.us/wiki/glossary-apfs), [exFAT](https://storagestudio.us/wiki/glossary-exfat), [Choosing an external drive](https://storagestudio.us/wiki/choosing-an-external-drive), [What a move keeps](https://storagestudio.us/wiki/what-a-move-keeps). - **How do I move apps to an external drive on a Mac and still launch them?** Dragging an app to another drive can break it, because macOS expects it in /Applications. Storage Studio relocates the app to your external drive and leaves a shortcut in place, so it still launches normally from Launchpad, Spotlight, and the Dock — and you can move it back in one click. (https://storagestudio.us/faq) - **How do I use an external SSD as extra storage on a MacBook?** Plug in a USB-C or Thunderbolt SSD and let Storage Studio pair it with your internal drive as one workspace. It moves big folders, libraries, and apps to the SSD with a shortcut left behind, so your MacBook behaves like it has a much bigger disk — fast enough to work directly off the external drive. (https://storagestudio.us/faq) - **Can I move my Photos or Final Cut library to an external drive?** Yes — large Photos, Final Cut, and iMovie libraries are common space hogs. Storage Studio relocates them to an external drive while keeping them usable, leaving a shortcut so your apps still find them. Moving a folder to your fast drive keeps its files' modified and created dates, permissions,… (https://storagestudio.us/faq) - **Will moving files to another drive break my apps or Spotlight?** Not the way Storage Studio does it. It leaves a shortcut (symlink) at the original location, so apps, Finder, and Spotlight resolve everything as if it never moved — and the move is fully reversible. (https://storagestudio.us/faq) ## What links here - [APFS](https://storagestudio.us/wiki/glossary-apfs) - [Choosing an external drive](https://storagestudio.us/wiki/choosing-an-external-drive) - [File ownership on external drives](https://storagestudio.us/wiki/file-ownership-on-external-drives) - [Setting up your drive](https://storagestudio.us/wiki/setting-up-your-drive) - [Switching to a new drive: Transfer Drive and Backup Drive](https://storagestudio.us/wiki/transfer-drive-and-backup-drive) - [What a move keeps](https://storagestudio.us/wiki/what-a-move-keeps) - [What to know about exFAT drives](https://storagestudio.us/wiki/exfat-drives) - [exFAT](https://storagestudio.us/wiki/glossary-exfat)