You’re just about to format your external drive with Disk Utility on your Mac.
And you’re going to format as APFS.
But you’ve noticed there’s another option. APFS (case-sensitive) and that’s made you pause.
Would it be a good idea for you to pick that option when you format your drive?
Or should you stick to the straight forward APFS format?
Read on and find out.
APFS VS APFS Case Sensitive
APFS is a Mac only file system format and is case in-sensitive. APFS Case Sensitive is an optional version of that file system.
APFS Case Sensitive as its name implies is sensitive to upper or lower case letters in the file name. A file or folder with the name of photo, or Photo are seen as separate files within the same folder.
At A Glance APFS Vs APFS (Case-Sensitive)
|Sensitive To File Name Case||No||Yes|
|Optimized For SSD’s||Yes||Yes|
|Older Mac Support||No||No|
Why Would You Pick APFS Instead of APFS Case Sensitive?
For the vast majority of Mac users. You’d simply pick APFS in Disk Utility when you’re formatting your external drive.
Modern Macs running Mojave, Catalina, Big Sur and Monterey have internal SSD drives installed. And those drives run APFS (Apple File System).
Plus, those Mac OS X versions support external hard drives. Or SSD drives formatted as APFS format.
The standard APFS is not case-sensitive. And this means that it treats files called photo and PHOTO as the same, when they are in the same folder. And will ask to overwrite one with other when you save.
If you wanted those files to hold different data in them. And for Mac OS not to overwrite one file with the other. You would need to save those files in different folders.
An APFS volume is happy for files to have the same file name. As long as those files live in different folders.
If you’re debating whether to format your external hard drive. Or external SSD as APFS then the post at this link will help. (Which To Pick?) Best Format For Mac External Hard Drive.
Versus When Would You Use APFS Case-Sensitive?
There are only rare edge cases where you’d pick a case sensitive version of APFS.
You wouldn’t pick it for a Mac boot drive.
And only where you’d a need an external drive to be sensitive to the case used in file and folder names.
What Does APFS Case Sensitive Mean?
It means you want folder names phoTo and pHoto to be two completely separate folders. One beside the other saved inside the same folder.
Where what you’re doing on your Mac’s external USB drive needs your Mac to treat a file saved as Photo. As a different file from a file saved as photo in exactly the same folder.
And most Mac users don’t need that feature.
Should I Use Case Sensitive APFS VS Standard APFS?
For most Mac users No.
Because most applications you’d run on your Mac computer. Including many of Apple’s own applications. Don’t recognize a case sensitive file system. And simply won’t work right.
That’s a clear downside to formatting your external drive in Disk Utility as APFS case sensitive.
On a standard APFS volume. Your folder photo, Photo and PHOTO are in the same place on your external USB drive.
Most applications you’d run on your Mac including the Apple ones expect that. And so are delightfully case insensitive.
The exception might be if you’re a developer. And your development target is an operating system with case sensitivity like Linux. Linux is case sensitive. So, in that case you’d want your code to work in the same way it would work in the deployed environment.
And if you’ve made the mistake of formatting your external hard drive. Or external SSD as case sensitive. Then realize your applications won’t work with a drive formatted that way.
The only way to change it is to reformat your drive with Disk Utility. And that means putting any files you have on the drive somewhere safe while you do that.
So that you can copy them back on after formatting.
A Bit Of Background On APFS And APFS Case Sensitive
Both APFS (Apple File System) and APFS case sensitive are at their core the same file system.
They are both made by Apple Inc and released in in 2017. APFS was designed for the faster speed of SSD (Solid State Drives) and flash drives.
It wasn’t until Mac OS Big Sur that APFS was supported for a Mac Time Machine backup.
Now APFS is the default file system on a Mac. And you can use either APFS. Or the previous file system Mac OS Extended Journaled on external drives.
The file systems equally support the use of and saving of large files.
As Mac file systems you can format an external drive in either file system format with Disk Utility.
And another Mac will recognize that external drive.
An APFS drive can’t be seen by a Windows PC. Not without the use of a 3rd party software solution. Called driver software.
With driver software installed. A Windows PC can view a APFS file system on that Windows computer.
An External Drive As APFS Or Case Sensitive
You easily create either Mac format using Disk Utility on your Mac. APFS file system or APFS Case-Sensitive.
APFS was made and is optimized for SSD’s (Solid State Drives).
You can equally use both formats on an external SSD drive or an external hard drive.
Click Here To Learn How To Format Your External Hard Drive With Disk Utility For Mac
Other Versions Of APFS And APFS Case-Sensitive
APFS has other options you’ll see in Disk Utility. There is an encrypted version of APFS. APFS Encrypted lets you secure your external drive and the files on that drive by adding a password.
Then no one can look at the files on your drive without entering that password.
And there is also APFS case-sensitive and encrypted. Where that version of the file system is not only sensitive to the upper and lower case use in the file system. The drive is also protected by a password.
You may well want to protect your files from prying eyes. If you do pick the version of APFS with encryption in Disk Utility. As that file system format version is the most widely supported by Apple software. And 3rd party application software on a Mac computer.
It would be rare instance indeed for a user to pick not only APFS case sensitive. But to add encryption as well. The need for that combination of Mac format is a true edge case.
Mac APFS VS APFS Case Sensitive FAQ
What Is The Difference Between APFS And APFS Case Sensitive
APFS Case Sensitive is a version of APFS. It’s a version of APFS that is sensitive to the case you use in naming files that are in the same folder.
And treats the files as different files. With different data inside them. To open the file PHOTO you’d have the type the file name as it’s stored on the drive. Matching the letter case you used to save the file exactly.
APFS is not case sensitive at all. And would see PHOTO and photo as the same file. And when you saved the file, it would write your changes onto the same file.
Is Mac APFS Case-Sensitive
No, the standard Mac APFS is not case-sensitive. The default APFS file system is case insensitive. And ignores whether you put in upper case or lower case characters when you type in a file name.
There is an optional form of APFS that is case-sensitive. It’s called APFS case-sensitive. And you can format a drive as APFS case-sensitive using the software utility Disk Utility on a Mac.
So, now you know the difference between the two. The case-sensitive version of APFS and the version normally used. – Simply APFS.
Picking to format your external drive as APFS case-sensitive would be rare. And only if you were sure that the applications you use supported the case-sensitive version.
While you are here do take a look at our other related articles about the different file system formats on a Mac.
ExFAT vs APFS (When To Use One Over The Other)
ExFAT Vs Mac Os Extended (When One Is Better Than The Other)
Time Machine APFS VS Mac OS Extended (Which and Why)
APFS VS Mac OS Extended (Compared) One 2 The Other
Mac OS Extended Journaled VS Case-Sensitive: Any Difference?
APFS VS APFS Encrypted (When You Need A Clear Comparison)
About Paul Gregory
I’ve been a system administrator for various corporates for 15 years. And as admin I’ve helped many with their Mac’s and there many Apple devices.
I’m excited by watching users, armed with a little knowledge take control of their Mac’s and their files. And why not?
When I’m not at work or working on the site I like to chill with few beers. And watch a bit of car racing. From Formula 1 to stock car racing. The competition is my thing.