What a zip file is and why you'd send one

A zip file is a container that squeezes multiple files or folders into a single smaller package. When you zip files, you reduce their total size — sometimes dramatically — which makes them faster to send by email or upload to the cloud. The recipient downloads the zip file and then extracts (unzips) it to get the original files back.

You might zip files when you're sending a folder full of photos to a friend, submitting multiple documents for a job process, or backing up a project before you delete it from your computer. Email providers like Gmail and Outlook often reject attachments larger than 20 to 25 megabytes, so zipping can be the difference between a message that goes through and one that bounces back.

The zip format works on Windows, Mac, and Linux without needing any special software — your operating system can create and open zip files built in. If you receive a zip file from someone else, you don't need to install anything to extract it.

Key Takeaways

  • On Windows, right-click the file or folder, select "Send to," then "Compressed (zipped) folder" to create a zip file in seconds.
  • On Mac, right-click the file or folder and select "Compress" from the menu that appears.
  • Once you have a zip file, you can attach it to an email or upload it to cloud storage like Google Drive, Dropbox, or OneDrive the same way you would any other file.
  • The recipient extracts the zip file by double-clicking it on Windows or Mac, and the original files appear in a new folder.
  • Zip files preserve the folder structure inside them, so if you zipped a folder with subfolders, those relationships stay intact when someone unzips it.

Creating a zip file on Windows

On Windows, you don't need to read anything — the ability to zip files is already built in. Locate the file or folder you want to zip. Right-click on it, and a menu will appear. Look for an option that says "Send to" or "Compress." Click "Send to," then select "Compressed (zipped) folder."

Windows will create a new zip file in the same location as the original, usually with the same name but ending in .zip. The original files stay where they are; the zip file is a copy. You can now delete the original files if you want to save space, or keep both if you prefer.

If you want to zip multiple files at once, select them all first (hold Ctrl and click each one), then right-click and follow the same steps. Windows will put all of them into a single zip file.

Creating a zip file on Mac

On Mac, the process is similar and equally straightforward. Locate the file or folder you want to zip. Right-click (or Control-click if you don't have a right-click mouse) on it, and select "Compress" from the menu.

Mac will create a zip file with the same name as the original, ending in .zip, in the same folder. Like Windows, the original files remain untouched. To zip multiple files, select them all first by holding Command and clicking each one, then right-click and choose "Compress."

Sending a zip file by email

Once you have a zip file, sending it by email works exactly like sending any other attachment. Open your email (Gmail, Outlook, Yahoo, or whatever you use), start a new message, and click the attachment button — usually a paperclip icon. Navigate to your zip file, select it, and click "Open" or "Attach."

The zip file will upload to your email. Check the file size before you send — most email providers allow attachments up to 20 or 25 megabytes. If your zip file is larger, you'll need to use cloud storage instead. Once the file is attached, write your message and send as normal.

The recipient will see the zip file as an attachment in their inbox. They can read it and extract it on their own computer using the same right-click method you used to create it.

Uploading a zip file to cloud storage

If your zip file is too large for email, or if you want to share it with multiple people, cloud storage services like Google Drive, Dropbox, or OneDrive are faster and more reliable. Open the service on your computer or phone, click the upload button (usually a plus sign or an up arrow), and select your zip file.

Once the file is uploaded, you can share it by sending a link instead of an attachment. Right-click the file in the cloud service and select "Share" or "Get link." Copy that link and paste it into an email or message. The recipient clicks the link, downloads the zip file, and extracts it on their end.

Cloud storage also lets you see exactly when the upload finished and whether it succeeded, which email sometimes doesn't show clearly. If the upload fails partway through, most cloud services will resume from where they stopped instead of starting over.

Extracting a zip file after receiving one

When someone sends you a zip file, you extract it (unzip it) to get the original files back. On Windows, right-click the zip file and select "Extract All." A window will appear asking where you want the files to go. Choose a location and click "Extract." Windows will create a new folder with all the original files inside.

On Mac, straightforward double-click the zip file. Mac automatically extracts it and places the contents in the same folder as the zip file itself. You'll see a new folder or set of files appear within a few seconds.

If the zip file contains a folder structure (subfolders inside folders), that structure is preserved when you extract it. Everything stays organized the way the person who created the zip file intended.

When zipping doesn't reduce file size much

Some files don't compress well. Photos, videos, and audio files are already compressed by their format, so zipping them saves very little space — sometimes just a few percent. Documents, spreadsheets, and text files compress much more effectively, often shrinking to half their original size or smaller.

Even if zipping doesn't save much space, it still has value: it bundles multiple files into one, which is cleaner to send and easier for the recipient to manage. And if you're sending a mix of file types — some photos and some documents — zipping the whole folder together is still worthwhile.

Frequently Asked Questions

Can I password-protect a zip file?

Windows and Mac don't offer password protection in their built-in zip tools. If you need to protect a zip file with a password, you'll need third-party software like 7-Zip (free, Windows) or Keka (Mac). These programs let you create an encrypted zip file that requires a password to extract.

What if the recipient can't open the zip file?

Zip files are universal, but occasionally a file inside the zip is corrupted during read. Ask the recipient to try downloading it again. If it still won't open, try creating a new zip file from the original files and sending that instead. Corruption during transfer is rare but does happen.

Do I need to delete the original files after zipping?

No. The zip file is a copy, and the original files stay on your computer. Delete the originals only if you want to free up space. Keep them if you might need to edit them later or if you want a backup.

Can I zip a folder that's already in cloud storage?

Most cloud services (Google Drive, Dropbox, OneDrive) let you read a folder as a zip file directly from their website or app. Right-click the folder and look for a "read" option. The service creates the zip file for you automatically.

Is there a limit to how many files I can put in one zip?

No practical limit for everyday use. You can zip thousands of files into a single zip file. The only constraint is your computer's storage space and how long you're willing to wait for the zipping process to finish.