Compression is the oldest trick in file sharing: squeeze a file down, send it faster, maybe even sneak it under an email limit. Every device you own can make a zip file today with no extra software, and it takes about ten seconds once you know where the button is.
But compression is only half the story. Zipping a folder of Word documents can cut its size by 80%. Zipping a folder of phone videos cuts it by about 2%, and now your recipient has to unzip before watching. Knowing when to compress matters as much as knowing how.
This guide covers the exact steps on Windows, Mac, iPhone, and Android, then gives you a simple rule for deciding between "zip it" and "just send a link."
Key takeaways
- Every device (Windows, Mac, iPhone, Android) can make a zip in about 10 seconds with no extra software installed.
- Text, CSV, and logs shrink 70-95% when zipped, but photos, video, and music save under 5% because they are already compressed.
- Zip is lossless: the unzipped file is byte-for-byte identical, unlike the lossy re-encoding chat apps force on your media.
- For media, or anything still over 200 MB after zipping, skip the zip and send a direct link instead (ShareIt.onl: up to 10 files, 200 MB, no account).
How to Zip on Any Device
Windows 10 and 11
- Select the files or folder in File Explorer (hold Ctrl to pick several).
- Right-click and choose Compress to ZIP file (Windows 11) or Send to > Compressed (zipped) folder (Windows 10).
- A new
.zipfile appears next to the originals. Rename it if you like, then share it.
No extra software needed. If you want stronger compression or password protection, the free tool 7-Zip typically shrinks files another 5-15% using its 7z format.
Mac
- Select files or a folder in Finder (hold Cmd to pick several).
- Right-click (or Ctrl-click) and choose Compress.
- macOS creates
Archive.zipin the same folder. Rename it before sending, since "Archive.zip" tells the recipient nothing.
One heads-up: zips made on a Mac include hidden files like .DS_Store and a __MACOSX folder. Harmless, but Windows recipients will see them.
iPhone and iPad
- Open the Files app and find your documents (save them to Files first if they live in another app).
- Tap Select, tap each file, then tap the three-dot menu and choose Compress.
- A
.zipappears in the same folder. Tap and hold it, choose Share, and send it anywhere.
Photos need one extra step: share them from the Photos app to Files first, then zip.
Android
- Open the Files by Google app (or Samsung's My Files).
- Long-press to select files, tap the three-dot menu, and choose Compress or Zip.
- Confirm, and the zip lands in the same folder ready to share.
If your file manager lacks a zip option, free apps like ZArchiver or RAR add it.
What Compresses Well, and What Doesn't
Compression works by finding repeated patterns. Text is full of them; photos and videos have already had theirs squeezed out by JPEG and MP4 encoding.
| File type | Typical size reduction | Worth zipping? |
|---|---|---|
| Text, CSV, logs | 70-95% | Absolutely |
| Word, Excel, PowerPoint | 30-80% | Usually |
| 5-40% (varies) | Sometimes | |
| RAW photos, TIFF, BMP | 20-50% | Yes |
| JPG, PNG photos | 1-5% | No |
| MP4, MOV video | 0-2% | No |
| MP3, AAC audio | 0-2% | No |
Real example: a 40 MB folder of Word reports zips down to about 8 MB, small enough to email anywhere. A 40 MB MP4 zips to about 39.5 MB, still far over every limit in our email attachment size limits table, and now it's wrapped in an extra layer.
The one case where zipping media still helps
Even when it saves no space, a zip bundles many files into one. Sending 200 photos as a single vacation.zip beats attaching them in batches of five. You're using zip as a container, not a compressor, and that's a perfectly good reason.
Tip: If the only reason you're zipping is to bundle files, you can skip the zip entirely with a direct link. ShareIt.onl lets you drop in up to 10 files at once and hands the recipient a single link, so there's nothing for them to unzip on the other end.
When Compression Isn't Worth It
Skip the zip when any of these apply:
- The files are photos, videos, or music. You'll save a rounding error and add an unzip step for the recipient.
- The recipient is non-technical or on a phone. iPhones and Androids can open zips, but it's an extra tap that confuses some people, especially with nested folders.
- You'd still be over the email limit anyway. If 300 MB of video zips to 297 MB, compression solved nothing. Go straight to a share link.
- Time matters more than bandwidth. Zipping 2 GB of data can take several minutes before the upload even starts.
In those cases, a direct transfer link is simpler on both ends. With ShareIt.onl you upload up to 10 files (200 MB total) as-is, pick an expiry from 1 hour to 7 days, and send one short link or QR code, with no account and nothing for the recipient to unzip. If you're moving video specifically, see the best way to share large videos, since chat apps add their own destructive compression on top.
Zip or Link? A 10-Second Decision Guide
- Mostly documents, under ~50 MB after zipping, going to email: zip and attach.
- Any photos or videos: share a link, zipping won't help.
- Mixed folder going to one person once: zip it, then share the zip via a link, so they get one tidy download.
- Bigger than 200 MB even after compression: split the work into two transfers, or use a cloud drive for that one file. The full menu of options is in how to send large files online.