ZIP to 7Z Converter
Processing entirely on your device — large files may take a moment.
ZIP Archive and 7-Zip Archive exist for different jobs: ZIP is the archive format everyone can open: built into Windows, macOS, and every cloud storage service. 7Z is ideal for big archives you store or share with power users; convert to ZIP when the recipient just needs to double-click.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How ZIP compares to 7Z
| ZIP | 7Z | |
|---|---|---|
| Compression | Deflate / store | LZMA / LZMA2 |
| Encryption | ZipCrypto (weak) or AES add-on | AES-256 native |
| Bundling | Multi-file with directory tree | Multi-file, solid mode |
| Best for | Universal sharing | Maximum compression, secure archives |
How to convert ZIP to 7Z
- 1
Select your files
Drag & drop your ZIP files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to 7Z". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted 7Z file individually, or grab everything at once as a ZIP archive.
About the ZIP format
ZIP (PKWARE, 1989) is the archive format the world agreed on: per-file Deflate compression (or plain store), a central directory that lets tools list and extract single files without touching the rest, and thirty-five years of universal support. Windows, macOS, Linux, phones and browsers all open ZIP natively.
Its compression ratio is middle-of-the-road next to 7z, and its encryption story is genuinely mixed: the classic ZipCrypto is broken, while AES-256 works only in tools that opted in. For maximum compatibility of everyday sharing, though, ZIP remains the only safe answer.
+ Strengths
- ✓Opens natively on every platform
- ✓Random access: extract one file, skip the rest
- ✓Thirty-five years of tooling maturity
! Limitations
- −Weaker compression than 7Z/RAR
- −Classic encryption (ZipCrypto) is broken
- −No built-in recovery records
About the 7Z format
7Z is the native format of Igor Pavlov's 7-Zip (1999), built around LZMA/LZMA2 compression — for years the ratio king against ZIP and RAR — with AES-256 encryption, solid archiving (similar files compress as one stream) and open, unpatented specifications. A 7Z of the same photos or code is routinely 20–40% smaller than its ZIP.
The trade-off is platform defaults: Windows Explorer and macOS Archive Utility do not open 7Z without third-party tools (7-Zip, PeaZip, Keka). It is the format for maximizing compression on your own terms, and for encrypted archives done properly (header encryption included).
+ Strengths
- ✓Top-tier compression ratio (LZMA2)
- ✓Real AES-256 encryption, optional header encryption
- ✓Open format, free tooling everywhere
! Limitations
- −No native OS support — recipients need tools
- −Solid mode makes single-file extraction costly
Why convert ZIP to 7Z?
Converting makes sense where the strengths of 7Z meet what ZIP cannot give you. Top-tier compression ratio (LZMA2) Meanwhile Weaker compression than 7Z/RAR One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this ZIP to 7Z converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for ZIP to 7Z?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Is there a size limit for archive conversion?
There is no upload cap because nothing is uploaded — the practical limit is your device memory. A few hundred megabytes of unpacked content works comfortably on a modern computer.
What about folders and directory structure?
The full directory tree is preserved: folders stay folders, and deep paths arrive exactly as they were packed in the ZIP file.