Resources » Other Topics (Non-PDF) » What is a ZIP file?

How Do You Create Zip Files?

A ZIP file is one of the best ways to transfer large amounts of information across the internet. If you download a file that has the .ZIP or .zip extension, or had to “uncompress” a file before, you’ve likely used a ZIP file already. But what is a ZIP file?

Imagine that you’re packing your car for a trip and need to bring 3 tents and 4 lawn chairs. In the normal world, you’ll need to carefully position these objects, so you can fit everything in your car. However, imagine that instead, you could compress the 3 tents down to a single dense object called “T”. You would similarly compress the lawn chairs down to an object called “L”. You’ve saved a lot of space doing this, but need to know how many tents that T contains and how many lawn chairs that L contains. So, you call the first object T3 and the second object L4 so when you’re unpacking, you know how many tents and lawn chairs you have. 

This is, in effect, the same way that data compression works. A program looks for repeated variables, strings of code, and other information that it can then store in a simpler format that gives “instructions” of what it is when it’s unpacked. This stored information is called a ZIP file and saves a lot of memory space so that it’s easier to send and download across the internet. When you receive a ZIP file, you’ll need to unzip it to access the information inside. 

That’s the technical explanation. The short answer is: A zip file is a squished version of larger files, and it could be one file or several files that have been highly compressed and changed into a new file format with a .zip extension.

Zip vs Compressed PDFs: What’s the Difference?

A compressed file retains the original file format, but through technology, some of the elements of the original file are removed, making it smaller. When you compress a PDF, for example, the file format is still a PDF. When you zip the PDF, it’s now a compressed file with a .zip extension. 

How Do You ZIP a File?

Zipping a file is easy to do on both Windows and Mac. Both systems can zip files without any external programs. These steps will actually work with any file type, including PDFs or a mix of files like JPG, PDF, DOC, and more. 

Zip a PDF on Windows 

  • Put the information that you want to zip inside a file or folder
  • Right click that file or folder and select Send to and then Compressed (zipped) folder
  • You will see a folder with a “zipped” icon in the same location

Zip a PDF on a Mac

  • Put the information that you want to zip inside a file or folder
  • Control-click the folder and then choose Compress from the shortcut menu
  • You will see a compressed file with the same name appear in the same location

You will notice that once you zip a file, the memory size of it will typically decrease. It will be much easier to send and download the file across the internet.

How Do You Unzip a File? 

You can unzip a file easily on both Windows and Mac without any external programs


  • Find the zipped folder you want to extract
  • Right click on the folder and select Extract All and then choose a location for the extracted files to be located
  • Note that a zipped file can have multiple files within, so extract a zipped file into a folder


  • Locate the zipped folder you want to open
  • Double click the ZIP file

Unzipping a file can take some time, depending on its contents, as your computer has to essentially “re-build” the file based on the ZIP.  

Can You ZIP a PDF?

Yes, you can technically ZIP a PDF. 

A ZIP file is a way to conveniently move data and programs that have a large file size across the internet. Similarly, when you convert a .doc, .docx, or other file to a PDF, you’re putting it in a simpler format that preserves your formatting settings. Single-page PDFs rarely have large file sizes, so it’s unlikely you’ll need to ZIP a single PDF. If you’ve got an ebook in the form of a PDF, then zipping it makes it easier to share.

However, if you’re moving multiple PDFs at a time, it can sometimes be convenient to put the PDFs into a single file and then ZIP that folder to be sent out in a single email. PDF.Live offers PDF compression services for free, but this simply reduces the size of the PDF; the output is still a .pdf file. Give it a try: To compress PDFs, drag and drop your PDF into our Compression Tool

If you uncompress a ZIP file and find a .doc or .docx file within, you can also use PDF.Live’s Conversion Tool to convert the files to a PDF. 

If you put PDFs into a ZIP file, you do not need a convert ZIP to PDF tool, as you just need to follow the above instructions to uncompress a ZIP file. You do not need a specialized tool to unzip a ZIP file if you are on Windows or Mac. Also be aware that not all ZIP files contain plain text that fits in a PDF. Trying to convert a ZIP file directly to a PDF would be like trying to camp without first unpacking those tents and lawn chairs.