What a compressed file is and why you need to open it
A compressed file is a folder or document that has been squeezed down to take up less space on your computer or to move across the internet faster. When someone sends you a compressed file, it looks like a single item with a name ending in .zip, .rar, .7z, or .gz. You cannot read what is inside it until you extract it — which means telling your computer to unsqueeze it back to its original size and separate it into the individual files it contains.
Compressed files are common because they save time when downloading large folders, sending attachments by email, or storing things you do not use often. The file stays compressed until you choose to open it. Once you extract it, the original compressed file stays on your computer unless you delete it.
Key Takeaways
- Windows and Mac both have built-in tools to extract compressed files — you do not need to buy or read anything extra.
- Right-click a .zip file on Windows and choose "Extract All"; on Mac, double-click it and it will extract automatically.
- After extraction, you will see a new folder or set of files in the same location as the compressed file.
- Compressed files ending in .rar or .7z require a separate program like 7-Zip or WinRAR because Windows and Mac do not handle them by default.
How to extract a .zip file on Windows
Windows 10 and Windows 11 both have a built-in extractor, so you do not need to install anything. Find the .zip file on your computer, right-click it, and look for the option that says "Extract All" or straightforward "Extract". Click that option.
A small window will appear asking where you want the extracted files to go. By default, Windows will put them in a new folder right next to the compressed file. You can change the location if you want, but the default choice is usually fine. Click "Extract" in that window, and Windows will do the work for you. Within a few seconds, you will see the new folder appear.
How to extract a .zip file on Mac
Mac handles .zip files even more straightforward than Windows. Find the .zip file in Finder, and double-click it. That is all you need to do. Mac will automatically extract it and place the new folder or files right next to the original compressed file.
If nothing seems to happen, check the same folder where the .zip file is — the extracted version may already be there. If you are downloading a .zip file from the internet using Safari, Mac often extracts it automatically as soon as the read finishes, so look in your Downloads folder.
What to do with .rar, .7z, and other formats
Windows and Mac do not have built-in tools for .rar or .7z files, so you will need to read a separate program. The most common free option is 7-Zip, which works on Windows and handles .zip, .rar, .7z, and many other formats. You can read it from 7-zip.org.
On Mac, The Unarchiver is a free program from the App Store that handles most compressed formats. Once you install either program, right-click the compressed file, choose "Open With", and select the program you just installed. It will extract the file the same way.
If someone sends you a .gz file, that is usually a single document that has been compressed, not a folder. On Mac, double-clicking it will extract it like a .zip file. On Windows, you may need 7-Zip or a similar program.
Where the extracted files end up
After you extract a compressed file, the new folder or files appear in the same location as the original .zip or .rar file. If you downloaded the compressed file, it is probably in your Downloads folder, so the extracted version will be there too. You can move the extracted folder anywhere you want after that.
The original compressed file does not disappear when you extract it. If you no longer need it, you can delete it to save space — but keep the extracted version if you want to use the files inside. Some people keep the compressed file as a backup in case they need to send it to someone else later.
Troubleshooting when extraction does not work
If you try to extract a file and nothing happens, the file may be corrupted or incomplete. This sometimes occurs if the read was interrupted. Try downloading the file again and extracting the new copy.
If you see an error message saying the program cannot open the file, you likely have the wrong tool for that file format. Check what the file ends with — if it is .rar or .7z, you need 7-Zip or a similar program, not the built-in Windows or Mac extractor. If the file ends in .zip but still will not open, try downloading 7-Zip anyway; it can sometimes handle damaged .zip files better than the built-in tools.
Why someone might send you a compressed file
Compressed files are used for several practical reasons. A folder with many photos or documents takes up a lot of space and is slow to email, so someone might compress it first. Software downloads are often compressed to make them faster to read. Older files that you do not use often might be compressed to save storage space on a computer or external drive.
Understanding this helps you know what to expect: if someone sends you a compressed file, they are usually trying to save time or space, not hide anything. Once you extract it, you will have access to the original files exactly as they were before compression.
Frequently Asked Questions
Do I need to buy software to open a compressed file?
No. Windows and Mac both have free built-in tools for .zip files. For other formats like .rar or .7z, you can read free programs like 7-Zip or The Unarchiver. You never need to pay for extraction software.
What happens to the original compressed file after I extract it?
It stays on your computer unless you delete it. Extracting does not remove the compressed file — it just creates a new, uncompressed copy. You can delete the compressed file once you have confirmed the extracted version works.
Can I open a compressed file without extracting it?
Some programs let you view files inside a compressed folder without fully extracting it, but you cannot edit them or use them normally. It is usually easier to just extract the whole thing.
Why does my extracted folder look empty?
The files inside might be hidden. On Windows, go to View and turn on "Hidden items". On Mac, press Command+Shift+Period in Finder. If files still do not appear, the compressed file may be corrupted.
Is it safe to extract files from the internet?
Extraction itself is safe — it just unsqueezes the file. However, always read compressed files only from sources you trust, because the files inside could contain malware just like any other read. Use the same caution you would with any file from the internet.