Open a ZIP file
Drop a .zip archive and see what is inside right away, with the size and date of every file. Then download only the one you need, instead of extracting everything. The archive stays on your device.
It stays on your device and is never uploaded anywhere
🔒 The archive is opened right here, inside your browser. No upload, no server, no copy left anywhere.
What it is actually for
Windows, macOS, Android and iPhone already open ZIP archives on their own, so this page is not trying to replace an archiver. It helps when that road is closed or awkward, on a phone for instance, where extracting everything fills the storage with things you do not need, or on a work computer where you cannot install software. You open the archive, look at the list, download the one photo or the one invoice you care about and close the tab.
How an archive is read without extracting it
A ZIP keeps its index at the end, not at the start. A final block (the EOCD) says where the file list lives, and that list carries for every entry the name, the original size, the compressed size, the date and the exact point where the content begins. That is why the list shows up instantly even on an archive of several hundred megabytes, since only the index is read. The real content is decompressed only when you press Download or Look inside, and only for that one file. Deflate decompression is done by the browser itself.
The check an archiver runs and never shows you
Every ZIP entry carries a CRC32, a 32 bit check value computed on the original file. After decompressing, the page recomputes that value and compares it. If it does not match, what comes out differs from what went in and the archive is damaged, almost always because a download stopped halfway. In that case you get a warning instead of a broken photo and no explanation.
Odd names and folders nobody put there
If the names look full of wrong characters, the archive was usually built by an old program that does not use UTF-8. Here every name is tried as UTF-8 first and then with the old DOS CP437 table. The __MACOSX folder and the .DS_Store or Thumbs.db files are added by macOS and Windows on their own, they are not part of what somebody sent you, so they are hidden and counted separately. Sizes are in KB of 1,024 bytes, like in a file manager, and the date is the clock of the computer that built the archive.
What it does not do, plainly
It does not open password protected archives, neither ZipCrypto nor AES, and the password is never asked for and never guessed. It does not open .rar, .7z, .tar.gz or .tar.xz, which are different formats. It neither creates nor edits archives, and it pulls out one file at a time instead of extracting everything into a folder. Multi volume archives (.z01, .z02) need every piece together and a real program. Everything else happens in the browser, so the archive never leaves your device. You can even go offline before opening it and the page keeps working.