How to Reduce The Size of a Zip File ?

👤 Diwas Poudel    🕒 10 Nov 2022    📁 TECH

Having a compact and small file can go a long way. Yet, there are a lot of questions that need some clarification about compressibility. Can you further zip a zip file? Does it always decrease the file size? What files can we zip and what is the result of zipping them? We’ll be answering these questions in today’s article.

Can you even do it ?

Zip files allow us to take multiple files or folders and combine them into a single file, saving a lot of storage space and increasing the efficiency of your computer. . Windows( Windows Compressed Folders) and Mac(Archive Utility Tools) can do this with the built-in tools. You can use the option for maximum compression or use a more optimized system like kzip. However, zip is already an old compression system and has become rather obsolete.

You may have also wondered if you could zip a zip file, and the answer is that there are no restrictions on zipping existing zipped folders.

Does Zipping an Already Zipped File Help?

No, it doesn’t. Compression helps you identifying and  removing redundant information from the data provided and if successful, the zipped result will be less than the input. Compressing an already compressed file doesn’t cause any harm. But it doesn’t bring about any good changes either. You won’t be able to achieve much by zipping a zip file. It’ll be like beating a dead horse. To get better compression than Zip, we’ll have to use a better compression algorithm than Zip.

📚 It is important to note that the zipping process involves lossy compression, therefore the quality of the contents is never diminished/reduced.

Zipping Files, Does it help every time?

Zipping can decrease the size of some files by a large margin. For some files though, compressing brings about more problems than leaving them. Examples of such files are Audio, Video, and Image Files. Sometimes, compressing these files results in a size increase than a decrease (However, there is a way to compress them as well. We will be checking those out down below). We can also compress Microsoft Office’s DOCX, TXT, and RTF files. But you don’t need to, because they are already lightweight.

Sometimes compression tools are incorrect and cause mistakes in a few bits in a zip file, preventing the entire Zipped folder from being unzipped, therefore choose your zipped tools carefully.

Also read : Show all files and folders in MB/GB in Windows 11/10

How to Reduce the Size of a Zipped File?

There are many ways to compress a file. Zip is the default provided in windows and mac. To reduce the largest size of files using Zip, you can follow the steps given below:

Use Different Compression Options

You can also try using different combinations of compression options that are provided in apps like WinRar and WinZip. Here are some of the things that you can change and how that change will affect the outcome of compression:

  1. Archive Format
    Choosing the best archive format is the most important. RAR is a better archive format than Zip or 7z. RAR archives compress files better. So, you can have some extra compression which means more storage space. If you’re unsure about RAR, always use the default Zip file. 
  2. Time Taken for Compression
    Under the “Compression Method”, the dropdown will show some options. If you’re not short on time, you can use the “Best” compression option. This compresses the files to the absolute maximum. So, you will achieve the smallest file size. Faster compression usually means that the compression won’t be as good as the slower method.
  3. Dictionary Size
    Bigger the dictionary size, the better the compression. However, this also causes the compression to go much slower. So, you can try and stick to the 1024KB option unless you have a well-specced PC.
  4. Split the File: You can use the same tool used for “compression options” to separate a single Zip file. This will not decrease the total size but it'll make sure that you can share the file in smaller chunks. This is useful for file sharing in apps like discord where the default limit is 8MB.

Configure WinZip 

When you install WinZip, there is a default configuration saved. The default compression setting is used every time a zip file is created. The default compression is legacy compression. The legacy compression creates a .Zip file. You can change this to create better compressed .Zipx files. Here’s how to do that:

  • Open WinZip
  • Click on Settings and open WinZip Options.
  • There, go to the General tab
  • Click on the button next to “.Zipx: Best Method (smallest Size)
  • Click OK
  • Close WinZip

Use Better Option than Zip

7 zip’s 7z and WinRar’s RAR compression algorithm are better options than the default Zip. These systems are more modern and can offer much better compression. You can use these apps to compress apps and get better results. Both these apps have paid and free options. However, the free option covers all our needs and much more.

7zip and winzip

How to compress Audio, Video, and Image Files? 

Audio, Video, and Images are different from the different folders that we compress generally. Sometimes, compressing audio and video as we do with other files will result in no change in the file size because they are already in high compressed state. But there is a way to compress all these using different applications and methods. 

  • Audio
    Audacity is a great free and open-source application that is used to record, edit or change an already-edited audio file. The best part about using audacity is that it can be used in a range of operating systems from Windows to Linux. It is a simple tool and can easily reduce the file size by a big deal. 
  • Video and Image Files
    A video file and an Image file both work based on pixel density. A 1920X1080 video or image means that there are 1080 pixels vertically and 1920 horizontally. It means that this is a good-quality visual. However, it also means that it takes up a lot of space. To compress these, you can use any online conversion tool like Compress Jpeg for photos and for Videos.
Also read : An Ultimate Guide to Popular Image Formats

How to Compress Already Compress PDF ?

PDF files are already zipped, so they are compressed, and if you want to further compress them, you can use Windows Zip. When you do so, the size of the PDF Zip file decreases.


Overall, zipping previously zipped files favors some sorts of files, and if you employ advanced compression technologies than previously done, you will obviously reap some benefits.

Article by : Adamya Neupane