## The Three Main Archive Formats
### ZIP — The Universal Standard
ZIP was created by Phil Katz in 1989 and is now supported natively by every major operating system.
**Key facts:**
- Built into Windows, macOS, Linux without any software.
- Each file is compressed independently — you can extract individual files without decompressing the entire archive.
- AES-256 encryption available in ZIP64.
- Supported by every email client, CMS, and file manager.
**Compression**: good, but not the best. Uses DEFLATE algorithm.
**When to use ZIP**: always when you're sharing with people who might not have specialized software. Maximum compatibility.
### RAR — Better Compression, Proprietary
RAR was created by Eugene Roshal in 1993. "RAR" stands for "Roshal ARchive."
**Key facts:**
- Proprietary format — you need WinRAR to *create* RAR files. Opening is free with 7-Zip, The Unarchiver, etc.
- Better compression than ZIP, especially for large files.
- Built-in file repair and recovery records.
- Multi-volume archives (split files) work seamlessly.
- Popular for distributing large files on download sites.
**Compression**: better than ZIP, competitive with 7Z.
**When to use RAR**: when distributing large multi-part archives and you control the creation side.
### 7Z — Best Compression, Open Source
7Z is the native format of 7-Zip, created by Igor Pavlov in 1999.
**Key facts:**
- Open source format and software.
- The best compression ratio of the three — typically 30-70% better than ZIP.
- Supports AES-256 encryption on both filenames and content.
- Multi-volume archives supported.
- Slower compression speed (especially at maximum settings).
**Compression**: the best available in this comparison.
**When to use 7Z**: when compression ratio matters most and recipients can install 7-Zip (free).
## Compression Benchmark
Compressing a 500 MB folder of mixed files (documents, images, code):
| Format | Result size | Compression ratio | Speed |
|---|---|---|---|
| **ZIP (default)** | 320 MB | 36% reduction | Fast |
| **RAR (normal)** | 290 MB | 42% reduction | Medium |
| **7Z (normal)** | **260 MB** | **48% reduction** | Slow |
| **7Z (ultra)** | **240 MB** | **52% reduction** | Very slow |
For already-compressed content (JPG, MP3, MP4): all formats achieve <5% reduction — compression is ineffective on pre-compressed data.
## Compatibility Summary
| Format | Windows | macOS | Linux | iOS | Android |
|---|---|---|---|---|---|
| **ZIP** | ✅ Native | ✅ Native | ✅ Native | ✅ Files app | ✅ Native |
| **RAR** | ❌ (7-Zip) | ❌ (Unarchiver) | ❌ (unrar) | ❌ | ❌ |
| **7Z** | ❌ (7-Zip) | ❌ (Keka) | ❌ (p7zip) | ❌ | ❌ |
## Encryption Comparison
All three support encryption, but with important differences:
| Format | Encryption | Encrypts filenames? |
|---|---|---|
| ZIP | AES-256 (ZIP64) | ❌ (visible) |
| RAR | AES-256 | ✅ (optional) |
| 7Z | AES-256 | ✅ (always) |
For sensitive data: 7Z or RAR offer filename encryption — zip shows the filenames even without the password.
## Recommended Tools
**Windows:**
- [7-Zip](https://www.7-zip.org) — free, handles ZIP, RAR, and 7Z.
**macOS:**
- [The Unarchiver](https://theunarchiver.com) — free, App Store.
- [Keka](https://www.keka.io) — free download or paid App Store.
**Linux:**
- `p7zip-full` — `sudo apt install p7zip-full` (handles all three).
## Converting Between Formats
- [ZIP to 7Z](/convert/zip-to-7z) — for better compression
- [7Z to ZIP](/convert/7z-to-zip) — for maximum compatibility
- [RAR to ZIP](/convert/rar-to-zip) — universal sharing
- [ZIP to RAR](/convert/zip-to-rar)
## The Bottom Line
| Situation | Best choice |
|---|---|
| Sharing with anyone | ZIP |
| Maximum compression, open source | 7Z |
| Large multi-part archives | RAR or 7Z |
| Encrypted archive with hidden filenames | 7Z or RAR |
| Email attachments | ZIP |
Guide