Open a .7z online
Open, browse, preview, or extract a .7z in your browser — no 7-Zip install, no upload.
Drop your .7z anywhere on this page
Decoded entirely in your browser via WebAssembly — your file is never uploaded.
A .7z is a compressed archive built on the open 7-Zip format — it bundles many files into one and shrinks them with LZMA/LZMA2 compression, usually to a smaller size than ZIP. To use the files inside you open or extract it, and because Windows Explorer and macOS Archive Utility do not understand 7z, "7z online" usually means installing 7-Zip first. ZipTool skips that: you drop the .7z on the page and it is decoded right in your browser by a WebAssembly build of 7-Zip, with nothing uploaded and nothing installed.
You open the page, drop the .7z onto it (or paste a direct URL), and the file tree renders locally. Browse the contents, search by name, and preview text, code, images, audio, video, and PDFs without unpacking anything to disk — then extract when you are ready. The whole decode runs in your tab; the network is used only to load the page (and, once, the decoder module). For the format background, see what is a 7z file.
What you can do with a 7z here
One archive, three workflows — pick the one that matches what you need.
- Browse and preview — look inside the 7z without writing anything to disk. Click any entry to read code with syntax highlighting, view images, play audio/video, or render a PDF. This is the online 7z viewer workflow.
- Extract — get the real files out. Use extract-all to write the original files to a folder you choose (Chrome/Edge) or download them as a bundle (Firefox/Safari). See extracting a 7z online.
- Search — filter the file tree by name across the whole archive to find one file in a large 7z without unpacking it.
How to open a 7z in your browser
No 7-Zip install, no Keka, no command line. The browser does the decode locally.
- Go to ZipTool and drag the
.7zonto the page (or use the file picker, or paste a URL). - The file tree opens on the left. Expand folders and search to jump to any entry.
- Click a file to preview it inline, or use extract-all to write everything to a folder.
- Nothing is uploaded — confirm it by opening a 7z and turning off your internet; browsing, previewing, and extracting keep working.
Why 7z is different from ZIP
7z is an open format (the 7-Zip project, by Igor Pavlov). Its signature strength is compression ratio: LZMA and LZMA2 typically produce smaller archives than ZIP's Deflate, especially across many small files, because 7z can treat the whole archive as one solid stream. The trade-off is reach and cost — the built-in OS tools do not speak LZMA, so recipients need a 7-Zip-compatible extractor, and extraction uses more memory and time than ZIP. That is also why a browser decoder is so useful: it removes the "install 7-Zip" step entirely.
Unlike RAR, 7z's encryption is supported here: a password-protected 7z uses AES-256, and ZipTool decrypts it in the browser once you enter the password. You can open and extract a 7z, including an encrypted one, but you cannot create one — ZipTool can create and convert to ZIP, TAR, and TAR.GZ instead. See create a zip online. For the full walkthrough, see how to open a 7z file.
Honest limits
A browser-based 7z tool is capable, but it has real boundaries worth knowing.
- Large 7z archives are heavy. LZMA decoding is more CPU- and memory-intensive than ZIP, and a solid archive is one stream. Very large 7z files can be slow or exhaust a browser tab's memory.
- Encrypted 7z needs the password. ZipTool decrypts a password-protected 7z when you supply the password; it cannot bypass encryption you do not have the key for.
- Extract-to-folder needs Chrome or Edge. Writing a real directory tree uses the File System Access API, absent in Firefox and Safari; there you download the contents as a zip instead.
- You cannot create a 7z. Use the desktop 7-Zip program to produce one. ZipTool writes ZIP, TAR, and TAR.GZ.
Frequently asked questions
How do I open a .7z file online?
Open the page and drop your .7z onto it. ZipTool decodes the archive in your browser using a WebAssembly build of 7-Zip — no install, no upload. The file tree appears, and you can browse, search, preview, and extract the contents. For the full steps, see how to open a 7z file.
Why will Windows or macOS not open my .7z?
The built-in tools do not understand 7z's LZMA/LZMA2 compression, so they refuse the file. You need a 7-Zip-compatible decoder. ZipTool provides one in the browser with no install, or you can install the desktop 7-Zip program.
Do you upload my 7z?
No. The 7z is decoded entirely in your browser using a WebAssembly 7-Zip module; your file contents are never sent to a server, never stored, and never handed to a third party. The only network traffic is the page itself and a one-time fetch of the decoder. Confirm it in DevTools and by disconnecting from the internet after the page loads — everything keeps working.
Can it extract a password-protected 7z?
Yes, when you have the password. 7z uses strong AES-256 encryption, and ZipTool decrypts it in the browser once you enter the password. It cannot open an encrypted 7z without the key. (Encrypted RAR, by contrast, is not supported.)
Is opening a 7z online free?
Yes. Browsing, searching, previewing, and extracting a 7z is completely free, with no account and no install. The decoder runs locally; there is no per-file paywall.