What is That "__MACOSX" Folder in Zip Files? 

A similar file is the ".DS_Store" file you sometimes see in Windows folders that may be shared over the network with macOS computers. macOS uses that file to store information about the folder itself such as the sort order and view style.

FINALLY! I was wondering about this for _so_ long. _(don't know why I never Googled it but still)_

As someone who has only used Windows and Linux my whole life I never questioned it. In fact, I always just thought, "Lol, Mac users need a special version of everything? Okay." Interesting to learn there's more to it

Why does JPEG contain metadata related to text encoding? Well, JPEG is a format that's widely used in photography, and there's this thing that's called EXIF data. EXIF data are metadata that is stored alongside the actual image data, and contain informations such as the light exposure time, the ISO number, the aperture f-stop, the focal point, and in some cases also GPS coordinates, and many more (comments, such as the camera model, serial number, etc.) - This kind of stuff is obviously in text format, and needs some sort of encoding. This is what the text encoding metadata is used for.

The ._MACOSX folder is very useful for me because as I work with InDesign files on Windows, when they're created on a mac system the old Type1 fonts are always 0Kb and cannot be used. But the 'real' fonts are stored in that ._MACOSX folder, so I can rescue them from there. 🙂

5:40 you can also use HxD to view the raw data of a file, in a better display, including both the readable characters version, and the raw hex data

The only thing I know that still uses resource forks are Type1 fonts. Those were quite common especially for professional printing, and since Adobe will stop supporting them next year, you‘re becoming quite aware how many jobs still use them, as InDesign displays a warning message if a job contains T1 fonts. It was always fun when a Windows user did something to a job, resulting in 0 Byte font files, that were useless since the resouce fork was missing…

And what about the .DS_STORE files on a mac? For example I see them if I copy folders on a USB from a mac, and plug it in to my Windows laptop.

Back in the days when we used MacOS 9, we did not have to use extensions like .EPS .PDF .Ai .doc .xls etcetera. You just typ in the name and that's it. MacOs will automatically open the right applications because of those resource forks. The files will contain the right image of a particular application. If you changed a text file .txt into .pdf it still will be opened by the text editor. It was a beautiful time not having to worry what kind of extension a file needed. You will recognize the file by its icon that refers to the application. And if you don't have that particular application you will get another icon that shows a missing application for that file..... That is why old Macs can still see newer Mac files on new systems

I swear you just keep making videos answering questions we have all wondered but never though to check

I believe part of what's stored in that macOSX folder is the files' positions within the folder(s), since Macs allow you to place files anywhere within a folder visually, unlike on Windows where they have to appear with some sort of ordering

You're the only channel that covers obscure little questions and suggestions about I.T. I think it makes your channel unique.

Thanks for the nice explanation man!

Thank you so much for having actually good captions!!! I know it’s effort but I Jude want to let you know I appreciate it :)

Hmm, this is what I kind of thought myself. Because in a video editing class I'm in at my high school. We use Mac Desktop computers for editing, and I saw that folder show up in archives containing clips. Seemly when I extract a file in my Linux laptop, this __MACOSX folder is also visible.

Interesting to see that you use MPC as your media player app. I was a huge fan, but since they stop further development I switched to VLC. But I miss all the features it had. Since I saw you using it I'm going back to it. Thanks for reminding me what I'm missing.

The UTF-8 text encoding for the JPEG file refers to the meta data itself that's included with the file. Right click and go to properties on an image file. There's information about the resolution, dimensions, etc. You can even have location data stored in the photo, along with an author, company name, etc.

I remember this on Nintendo Wii mods from some downloads on popular modding sites years ago

I remember seeing this folder when Jesper the end send these files to me back in 2014. And it was driving me crazy! Thanks!

Very good video Joe!

I actually use macOS myself as my main operating system. I own an iMac and MacBook Air which both use macOS Monterey. I can confirm that in the packages are folders called MACOS and Resources. I honestly didn’t know this myself and I’m glad you made this video. Thank you.

So, next video should be about System Volume Information, thumbs.db, desktop.ini and stuff?

I was recently wondering this as I am on macOS and I sent my friend (who is on Windows) a zip file and he was asking me what that folder is!

And that's why I'll stick with Unix for file management: a file is a file that never goes beyond it's size, it's type is determined by its header (and not a random extension), execution is a permission that can be granted or revoked at will and there's no intrusive or inaccessible metadata created without permission.

Very well explained. Thanks a lot.

Fantastic explanation 👍🏻👍🏻

Oh man the resource fork. Back in the days of pre-OS X, this was used to tell the computer what the file was. In the old days, Windows used file extensions to know if it was a jpg, doc, etc. But Macs did not. The file extension wasn't even needed, all of the info about what kind of data was stored in the resource fork. You could even have 2 files with .jpg extensions that would open in different programs because the OS didn't know that they were both the same file type, it just knew this file was created by Photoshop so Photoshop could open it. This is also how it displayed the icon for the file - by what program it was associated with. In the late-90's with OS9, when the internet became a thing, you had a control panel to map a downloaded file extension to an application. You could also copy/paste images into the display icon for the drive, file, folder, etc. Back in high school, we had a 'games' folder on the school computers, but, altered the icon on the folder so it looked like an ordinary file. There was an application called ResEdit that could alter this resource file. I made a slightly customized version of the Finder app for the computer we named 'Oscar the Grouch'. The trash bin was renamed 'Oscar's Home' as well as a few other things that normally you should not do.

That was a great topic. I've seen these folders when downloading images in vector format.

I was wondering about this just yesterday so you best believe I tapped the notification

This is the kind of content that makes you grow!

Aaahhh! Now I understand it! I always wondered about _MAXOSX

If you send the zip to a Windows (where you can see this MacOS folder), delete the MacOS folder from the zip, and then send it back to the same Apple device, can you still unzip it? Has anything changed from an Apple point of view?

Thanks for your sharing

NTFS is also bizarre. Each file might have more than one Stream (akin to the MacOS “Data Fork”). So you can send someone a text file of 5kb with an Alternative Data Stream of 50Mb with a virus, and the recepient will not even notice it by the file size. As far as I am aware MS have added this feature to have some level of compatibility with the Apples HFS+ file system.

Ah yes! Straight to the point

I watched this video 15 days ago when you posted this and today I found on my pc a MACOSX file

On legacy mac oses in the rsrc fork were also stored file type and creator (two sets of four letters) that enabled files not to need any extension to the file name to be recognised as its type and to open the correct application when double clicked on. You could also alter those to suit your needs, using ResEdit, Apple Script, or dedicated typer apps. At that time DOS was limited in file naming, while those old mac oses allowed for 32 char file names NOT needing a .XYZ at the end. Now when you drag and drop a file on an email, you strip away that rsrc fork. But if you compress it in an archive then it is preserved. The same with an ftp app, if you want to preserve all attributes or copy an app : compress it or it will not work.

Good Video!

I've become quite a fan of your helpful guides over the last couple of years. I have a suggestion for another, if you think you could help. It used to be so easy in Windows to set up sharing across a home network for your external USB drives, no matter which box they are connected to. This seems to have changed. After a Windows update some time ago now I found that, despite having all my drives set up to allow access to my laptop & tablet etc., the ones connected to my desktop (Windows 10 32bit (I know, I know. I need to upgrade!) always come up access denied. Yet I could always access drives that were connected to my laptop (also 32 bit Windows 10) from the desktop, and tablet. However, I recently emptied, and reformatted a drive that's connected to the laptop, & it now gives me the same trouble. Despite having set up advanced sharing, I can't access it at all from any other device. I also have a Seagate 2TB portable USB drive that point blank refuses to allow me to connect to it from anything other than the device it's plugged into. A video on troubleshooting this issue would be invaluable to more than just me, I'm sure.

Mac OS X has a annoying function of writing these files it over the network (can be disabled until you do every time you touch a Windows computer you're creating hidden files that you can see when you turn off hidden files or on hidden files ) and and FAT formatted drive which is annoying when your MP3 player tries to play the next 30 songs that are ._. It's a common recent search history in my windows XP system. I At least still use text clippings occasionally which supposedly use resource Forks. Finally a good explanation I've looked this up before.

Funnily enough, this happened to me yesterday! Thank you! I can now delete it off my android tablet.

I frequently get zip files from Mac users. To me it's just annoying data that I don't want on my system, so I wrote a script to extract the zip file, recursively go through folders and delete Mac added files, repack the files with 7-zip for better compression, and finally delete all the old files. I then added that script to the context menu for folders so I can drop zip files into that folder, and right click to clean and recompress them in one go.

Nice thanks for telling

Thanks so much for this explanation. Apple makes everything more difficult than it should be

in macOS you actually can see resource forks but only in terminal and it's in the same directory and there's no __MACOSX folder. i guess it's so you only see them if you're looking for it.

Interesting. I always thought it was a corrupted backup files. I always delete them because I didn't know what it actually does

Good Tip!!!

Needed this, lol

great content

I think these files are still used for tags like the coloured thing macOS can add near files/folder, with a right click. Or also for put a custom background on folders (yeah. usually for app installers, so they can make a background with a "Drag the file here" with an arrow.

Nice video! I always wondered this but never bothered to google it. Great video as always man. BTW I would love a ThioJoe iDubbbzTV collaboration!

"Apple stores data unintuitivly" Yet spotligt will find that one file you placed god knows where 10 years ago and named is something bizarre that you can't even remember Meanwhile Windows search struggles to even find a file within a folder

3:57 that binary file is a unix executable if you run it via terminal it will open the program so it the main part of the app

Nice video! one question: MacOS supports assigning tags to files. This information is also stored in the resource fork?

Nice!

Theo is the best

That's where your self respect is filed away after throwing your hard earned money at the most unscrupulous company, CrApple... 🙃

jpegs actually store their own metadata as text (that’s why you see the text encoding declaration). metadata such as the gps location the photo was taken at

Yeah, I never really questioned it. I actually use that folder when the app wont open. (Minecraft Launcher being like that alot)

I think the .app folders have always existed in OSX, I even remember seeing .app folders in OS9 or OS6, I don't fully remember but its older than OSX. Also, APFS is still brand new, before that we had HFS and HFS+.

Hi Thio do you have a video on different file systems, where you go in depth in them?

6:23 Idk when this was filmed or what operating system this is originating from but when iOS 15 and macOS Monterey came out came some OCR for text. It could be that the text format has to do with the OCR.

The text encoding on images exists because macOS has "Live Text" a feature that can read text on photos and you can copy-paste it!!

It's more like dealing with the post office and it's just some rules for file mail. The Zip lady says: "You missed the customs declaration..."

I always deleted that folder. I'm paranoid. I delete first and not ask questions later.

Very cool

Text on a JPEG would be things like Author, Copyrights, etc…

in my opinion, macs make it easy to install most apps, ./is also used by linux too when it has hidden files, because both are based on unix with mac OS using something called darwin

Windows has a equivalent one as well. Edit: I had to sleep... Any Drive you plug into a windows system has folder placed in its root directory named System Volume Information.

If you open a Terminal window on a Mac and “ls -a” a folder on a USB device containing all these hidden files, you actually can see them. They just won’t be visible from the GUI at all.

Glad to see you turned a new leaf. Used to hate you for being a troll.

LOL - and on NTFS (Windows) that is stored in ADS (alternate data streams), accessible via [filename]:[streamname] (e.g. text.txt:addition)

those files would be hidden on linux too (hince linux also uses . at the beginning of filename to determine hidden files and folders)

Anthony Young + Linus Sebastian = Thio Joe

It's interesting how even on the latest macOS which is actually not macOSX and is just macOS 12, it still names the folder macOSX.

That __MACOSX reminds me of the C os dependant macros

Now I finally knew why… Also an unrelated question: What app are you using for the tabbed File Explorer?

No, APFS is a partitioning scheme. This happens on JHFS+ as well

I’ve never seen a file like that in my .zips

There are similar "forks" on NTFS and HPFS. They're called "streams" and could contain essentially anything, like completely different array of bytes. Except they're not limited to just two of them -- it could be a hundred or two hundreds -- don't know the exact limit there. Neither do I know how ZIP handles it. :)

Hay ThioJoe, I have a samsung s20 phone and sometimes it like glitches or is not working properly and I have to restart the phone but this is pretty constant is there any way to fix this problem. And I was hope you can help since you are pretty knowledgeable in technology. Love your videos you are great thanks 😊 👍

I know __MACOSX can store in DS_Store the arrange of icons so even if it’s other file system it can use that feature under macOS. What I would like to know is how a feature of macOS works, that is if you have a 1GB file in a folder and copy it 100 times the folder will not really be 100GB but 1GB actually, I don’t know if it’s the file system itself or that folder which stores information about how many copies there are to be able to link them all

4:51 tplink wifi adapter as flash drive lol

the point of it is to make the zip file size twice as big

JPEG might have exif information, and exif might contain a comment or description, and that is text, which might be encoded as UTF-8.

My laptop lenovo g580 current processor Intel pentium b950... can you suggest me compatible highest processor I could replace... I need help.

Interesting explanation on this topic. I would never have thought to look in those folders before. I caught the image that you showed of the executable file you were showing as a Unix executable. Does that mean that a macOS executable will run on Unix? What about Linux? Also, it was my understanding that when OSX came out, the X was supposed to be the Roman numeral ten, so when I see OSX, I say, "OS ten."

SO Will I be looking for ._MACOSXII folder, as we are on MAC OS 12 LOLS :) But a great video thanks…

So basically it's like thumbs.db on Windows. But instead of a file for a folder, it's for each main file.

[6:21] maybe the exif data is encoded with utf8.

In 2018, I tried to audition for Inanimate Insanity, so I downloaded their assets, and they had that folder. I tried opening the files in it, but with an error. Prolly meant for Mac os x flash users

how did you get tabs in explorer?

I like to store my forks separate from my knives and spoons.

3:11 so do you become and executive when others would get executed? How do I learn this power?

I just assumed it was just in case you downloaded the software for a Mac so the files are ready

😂😂 my question exactly!

Suddenly, NTFS Alternate Data Streams

Hi, what program do you use for tabs in Explorer?

I thought this was the mac version. Never had a mac so I had no idea how macos executables look like

Aha!! I knewed !! The MACOSX folder in a zip file means that the zip archive can be opened even on a mac operating system, that's interesting.