How to unzip files online
- Drop the ZIP into the box above, or press Choose file. A .tar.gz, .tgz, .tar or .gz file works the same way.
- Read the summary. It says how many files there are and how big they get when unpacked, and it lists anything worth knowing first: a password, names that look garbled, files that run programs, or a damaged archive.
- Press Download or Preview next to any file. Images, text, PDFs, audio and video open right on the page. A ZIP inside the ZIP has an Open button.
- To take everything, press Save all to a folder in Chrome or Edge, or Download a clean ZIP in any browser. Nothing was uploaded at any point.
When a ZIP will not open
Most "this ZIP is broken" moments have one of a handful of causes, and the page names the one it finds instead of a generic error. We built test files for each case and checked what comes out.
| What you see elsewhere | What is usually wrong | What this page does |
|---|---|---|
| "The compressed (zipped) folder is invalid" or "unexpected end of archive" | The download or copy stopped early, so the table of contents at the end of the file is missing | Reads each file's own header from the start and recovers every complete file. Test: cut off inside the 4th of 6 files → files 1–3 recovered byte for byte, file 4 named as cut off |
| The archive opens but nothing extracts | The file is really a RAR or 7z archive with a .zip name | Recognises the format from its first bytes and tells you which program opens it |
| A tiny .zip of a few KB that nothing opens | The link saved a web page — an error or a sign-in screen — instead of the file | Spots the HTML and says to download again, signed in |
| Only some files extract, or "unsupported compression method" | Those files were packed with BZIP2, LZMA or Deflate64 by 7-Zip or WinZip | Unpacks the rest and names the method of each file it cannot |
| Windows extracts everything except a few files | Names with ? : * or a reserved name such as CON, common in archives made on a Mac or Linux | Renames them when saving, so the rest of the archive still comes out |
| The .zip asks for the other parts, or is mostly empty | It is one part of a split archive (.z01, .z02…) | Says so; a split archive needs all parts and 7-Zip or WinZip |
| Some files come out but do not open | Their data was damaged inside the archive | Compares each file with its CRC-32 checksum and marks a mismatch, so you know which copy is bad |
Password-protected ZIPs
Type the password once and every locked file opens. It is checked on the smallest file first, so a mistake is reported right away as a wrong password, not as a damaged archive. It stays in the page and is never sent anywhere. This page does not try to guess passwords.
| Encryption | Made by | How strong |
|---|---|---|
| ZipCrypto | 7-Zip's default for .zip files, older WinZip, the zip -e command, many phone and NAS apps | Weak — keeps out a casual reader, not someone with cracking tools |
| AES-128 / AES-256 | 7-Zip (choose AES-256), WinZip, most current tools | Strong, as long as the password is long. Not every built-in extractor can open these; this page can |
AES archives also carry a short password check and an authentication code for each file. The first tells a wrong password apart from damage straight away; the second is verified as the file is unpacked, so a file damaged inside the archive is marked instead of passing as good.
Garbled file names
If a ZIP made on a Japanese computer turns 資料/見積書.txt into Äæù┐/î⌐É╧Åæ.txt, nothing in the files is wrong, only the names. Older tools wrote names in the computer's local character set and did not record which one, and the ZIP standard tells readers to assume the old American DOS set. When the page sees a name like that, a list of languages appears, each showing how the first name would read in it. We checked Japanese (Shift_JIS), Russian (CP866) and Turkish (CP857) archives; each came back with the original names once its language was picked. Saving to a folder or taking the clean ZIP keeps the corrected names.
Before you open files from someone else
A ZIP is a common way to get a harmful file past an email filter, because the filter cannot always look inside. The page reads every name before you open anything and points out:
- Programs dressed as documents — a name such as invoice.pdf.exe, where the real extension comes last.
- Files that run code — .exe, .js, .vbs, .lnk, .scr, .bat, .msi, .iso and similar. Normal in a software download, a warning sign in an archive you did not expect.
- Names that escape the folder — a path like ../../file can make a careless extractor write somewhere else on your drive. Saved from here, every file stays inside the folder you picked.
- Extreme compression — a small archive that would grow to many times its size, the sign of a ZIP bomb built to fill a disk.
- Links to other files on the computer that made the archive, which are listed but never created.
None of this proves a file is safe. It tells you what is in the archive before anything opens.
The clean ZIP
Download a clean ZIP builds a new archive from the files that unpacked and passed their checksum. It has standard UTF-8 names, no password, no __MACOSX or .DS_Store clutter and a complete table of contents, so a recovered download or an archive with garbled names becomes one that opens on any computer. Files that failed their check are left out and named in the summary. To pack your own files instead, use Create ZIP File.