How to Compress Files: ZIP, RAR & 7z Guide
Compressing files before sharing can reduce their size by 10-90%, depending on the file type. Here's everything you need to know about file compression in 2026.
How Much Can You Compress?
| File Type | Typical Compression | Why |
|---|---|---|
| Text documents (.txt, .csv) | 70-90% | Highly repetitive data |
| Office files (.docx, .xlsx) | 10-30% | Already partially compressed |
| PDF files | 5-15% | Already compressed internally |
| Images (.jpg, .png) | 2-5% | Already compressed formats |
| Video (.mp4, .mov) | 1-3% | Already heavily compressed |
| RAW photos (.cr2, .nef) | 20-40% | Uncompressed sensor data |
| Source code | 60-80% | Plain text, repetitive |
Key takeaway: Compression works best on text-based and uncompressed files. Videos, JPEGs, and MP3s are already compressed — zipping them won't save much space.
Windows: Create a ZIP File
- Select the file(s) you want to compress
- Right-click and choose "Compress to ZIP file" (Windows 11) or "Send to > Compressed (zipped) folder" (Windows 10)
- Name the archive and press Enter
For better compression, download 7-Zip (free, open-source) and use the 7z format, which compresses 10-30% better than ZIP.
Mac: Create a ZIP File
- Select the file(s) in Finder
- Right-click and choose "Compress"
- A .zip file will be created in the same folder
For better compression on Mac, install Keka (free) to use 7z format.
Linux: Command Line Compression
- ZIP:
zip -r archive.zip folder/ - 7z:
7z a archive.7z folder/ - tar.gz:
tar -czf archive.tar.gz folder/
ZIP vs RAR vs 7z
| Format | Compression | Compatibility | Open Source |
|---|---|---|---|
| ZIP | Good | Universal | Yes |
| RAR | Better | Needs WinRAR/7-Zip | No |
| 7z | Best | Needs 7-Zip/Keka | Yes |
Our recommendation: Use ZIP when sharing with others (everyone can open it). Use 7z when maximum compression matters and the recipient has 7-Zip installed.
When Compression Isn't Enough
If your files are still too large after compression (especially videos and images), use a file transfer service instead. FileDroppy handles files up to 500 MB (free) or 5 GB (Pro) without compression — just upload the original files and share the link.