--- title: "ZIP to 7Z Converter — Smaller Archives | Compress Pro" description: "Repack ZIP archives as 7Z right in your browser and shave off extra megabytes — LZMA2 compresses harder than deflate. No upload, free and private." canonical: https://compress-pro.com/zip-to-7z --- # Convert ZIP to 7Z. > Repack ZIP as 7Z for the strongest everyday compression. ZIP is universal; 7Z is efficient. Repacking a ZIP as 7Z re-compresses the same files with LZMA2, which routinely lands noticeably smaller on documents, code and mixed folders. **The conversion runs entirely in your browser** — drop a ZIP, download a 7Z. **No uploads · No ads · Free & open source.** ## How it works 1. Drop files anywhere on the page, click to browse, or paste with Ctrl/⌘ + V. 2. Pick a quality or preset — or set an exact target size and let the tool find it. 3. Compress, compare before/after, and download — individually or as a ZIP. ## Deflate vs LZMA2 in one breath ZIP compresses every file on its own with deflate, a 1990s algorithm tuned for speed. 7Z packs files into one solid stream and runs LZMA2 with a real dictionary over it, finding repetition across files — that is where the extra percent comes from, and why 7Z is slower to build. Going the other way is [7Z to ZIP](https://compress-pro.com/7z-to-zip); starting from loose files, the [archive tool](https://compress-pro.com/zip-files) creates either format directly. ## Frequently asked questions ### How much smaller does 7Z get? Depends on the content. Text, code, spreadsheets and databases often shrink 20-40% versus ZIP; photos, video and other already-compressed files barely move. The output size shows next to the input, so the verdict is immediate. ### What opens 7Z files? 7-Zip on Windows (free), Keka or The Unarchiver on macOS, p7zip on Linux — and any modern archive manager. What does NOT open them is the built-in Windows Explorer extractor before Windows 11 24H2, so know your recipient. ### Can I make the 7Z password-protected? Conversion keeps the output unencrypted so it opens without friction. To create an encrypted 7Z, use the Create op on the archive tab — it offers AES-256, optionally with hidden file names. ### Is it private? Yes. Archives are built and converted entirely in your browser — neither the archive nor the files inside it are ever uploaded, and any password you set is applied locally. The server does nothing but deliver this page. Want proof? Run one file through, switch your connection off, and run another — it still works. ## Related tools - [Convert 7Z to ZIP](https://compress-pro.com/7z-to-zip) - [Zip & Unzip files](https://compress-pro.com/zip-files) - [Convert RAR to ZIP](https://compress-pro.com/rar-to-zip) --- Part of [Compress Pro](https://compress-pro.com/) — every tool page has a markdown twin at `.md`. Full tool index: [llms.txt](https://compress-pro.com/llms.txt)