The ZIP file format
ZIP files are one of the most popular ways to save disk space and send large files and folders to other computers. The process for creating a ZIP file or folder is slightly different depending on what device you’re using, so here we’ll explain the best ways to do it for Mac and Windows users, before discussing alternative methods that are even more efficient and reliable.
A ZIP file is one or more files that have been compressed together in one location. When a file or folder is zipped, its contents are compressed, with redundant data removed, so they use and require a lot less data to store and share. The process is called 'lossless data compression', with lossless meaning that while the file size will be greatly reduced, the file itself won’t be affected. ZIP is a file archive format. There are others, like RAR and 7-ZIP, but ZIP is the most common.
Why should I zip files?
ZIP files can be extremely useful if you’ve got a large group of files or even just one massive file that you need to share with your team. A lot of email clients won’t allow you to share huge files, so file compression is often seen as one of the best solutions for sending bigger data. You can also use ZIP files to encrypt private data before sending it online.
How to zip a folder or file on Mac
For macOS users, if you’re compressing multiple files together, you’ll need to make sure they’re contained in the same folder. Ideally, you should create a new folder with only the files you wish to compress. You can then simply right-click or Ctrl-click that folder and select 'Compress Items'. The .zip file will be saved in the same location that the original folder is saved.
If you only want to compress certain files in a folder but not the entire folder, hold down the Command key and then click on whichever files you want zipped. When they’re all selected, right-click and select 'Compress [#] items'. All items will be compressed into a single ZIP file, called 'archive.zip'. You can change the name by right-clicking the file and selecting Rename. It’s the same process if you only want to compress one file – just right-click on it and select 'Compress [filename]'.
How to make a ZIP file on Windows 10
Using 'Send To'
The process is similar for Microsoft users. Make sure all the files you’re compressing are in one folder, right-click that folder, and then find the 'Send To' option. In the "Send To” menu, you should see the 'Compressed Folder' option. Click that, and your compressed file will be saved to your desktop.
To select multiple, but not all files in a folder, hold down the Ctrl key and click each file you want zipped. If all of the files you want to zip appear consecutively in the folder, you can click the first item, hold down the Shift key and select the last item, and then all files in between will also be selected. You can then right-click and compress all of the selected files. To compress a single file, simply right-click it and then follow the same steps.
Another way to zip files on Windows would be to select all the files you want compressed and, in the 'Share' tab of File Explorer, locate and click the 'Zip' button. This can be done on any Windows computer operating Windows 8.1 or higher, while with older computers you’ll need to use the right-click and Send To method.
How to open a ZIP file
To uncompress a zip file on Mac, simply double-click on it. Alternatively, you can right-click on it, hover over 'Open With' and select 'Archive Utility'. The file will unzip and a new folder will be created with all of the files, in the same location that the ZIP file is stored.
On Windows, you can view the contents of a ZIP folder without unzipping it, but can’t edit them unless you extract the files. To do so, right-click on the ZIP folder and select 'Extract All'. The files will be extracted and stored in the same location as the ZIP file, or you can set a different location by pressing 'Browse' in the Extract All wizard. You can also do the same for individual files within a zipped folder if you don’t want to extract everything at once. Simply right-click the file and select 'Cut', and then paste it wherever you want it saved.
Add files to an existing ZIP folder
You might already have a zipped folder that you need to add more files to, and fortunately on Windows this isn’t too complicated. Simply drag the new files or folders atop the ZIP file, like you would if you were adding a file to a regular folder.
For Mac, on the other hand, this isn’t possible without the use of a third-party service. While there are some third-party archivers like WinZip that are pretty well trusted, it can still be a major security risk, especially if you’re zipping private files. With that in mind, the safest way to add new files to a zip folder on Mac would be to create a new zip file from scratch.
How to create a ZIP file that’s password protected
Password protecting ZIP files is possible through Windows 10, to some extent. To do so, right-click on the ZIP file and select 'Properties'. From the 'General' tab, click 'Advanced'. Select 'Encrypt contents to secure data', click OK in the Advanced window, and then click OK in the Properties window to save your changes. You’ll notice that the file icon now shows a padlock. You’ll still be able to open the file like normal so long as you’re logged into your user account, but other accounts will not be able to access it. This is a decent method for protecting a ZIP file on your own computer, but doesn’t provide any security for sending the file elsewhere.
For Mac users, your options are even more limited. There’s no way to directly password protect a ZIP file on Mac. You’ve got to do a bit of legwork using Terminal, which is quite a complicated and, considering the other options available, unnecessary process.
Again, there are plenty of third-party apps that you can use to protect ZIP files on both Windows and Mac. However, this could be hazardous as it would require you granting a third-party access to your unprotected files.
Disadvantages of ZIP files
While for the most part ZIP files are an efficient solution for reducing file size, they don’t work as effectively for every type of file. For instance, MP4 and JPEG files are already highly compressed as they are, and zipping them won’t actually compress them much further. So, while ZIP files should always reduce file size, for certain files this reduction won’t be anything too substantial – you can only compress a file so much without damaging it. There is also the risk that files can be damaged or corrupted during the compression process. Furthermore, compressing a file involves a few extra steps, and sending compressed files can become a bit of a hassle – especially when there are alternatives that can get the job done far more efficiently.
Alternatives to ZIP files
Considering the limitations described above, you might find that compressing files isn’t really the best solution for you. ZIP files are a good way to save space on your device, but would mean that to use your file you would need to find the ZIP it was in and unzip it before opening it. This could easily become frustratingly time-consuming. You’d be better off seeking an option that lets you keep your files at their original size without taking up any space on your computer – and that’s when cloud storage comes in.
When you use Dropbox Smart Sync, you’re saving your files to an online server, so they don’t take up any space on your computer, and you can access them from anywhere that has internet connection. With Dropbox, you can upload files of any size, in any file format and sharing them with others just takes a few button clicks. You’re not risking files being corrupted during compression, you can upload effortlessly and send large files in an instant, and you save a few steps in the process.
Even if you still need to use ZIP files – you can save and send them from Dropbox, and even preview a zipped file through Dropbox itself.
If you download the Dropbox desktop app, then getting your files on Dropbox is as simple as just dragging them into the Dropbox folder. On the web app, you can drag and drop files straight into Google Chrome, Safari or whatever browser you’re using with the web app open. Then, sharing your files and folders is as simple as clicking Share and choosing who to send them to. Just like you can do with ZIP folders, you are able to password protect Dropbox files so that only those who are granted access and have the password can open them. You and your team can share and edit files and folders through Dropbox itself, without having to create and send new ZIP files with updated documents every time. Everything on Dropbox updates as you edit, making collaboration a whole lot more efficient.