How to open a .CPGZ file online
No extra software to download or install.
Pick your .CPGZ file
Drag it in or click to choose it. We read its contents list first, so it opens right away without unpacking everything.
Browse what's inside
See every file with its size, how much it's compressed and its date, and search by name across all the folders.
Preview or download
Click a file to preview text or images, or save just that one. Need everything? Download it all as a single ZIP.
About .CPGZ files
What a .CPGZ file is, and what's inside it.
A CPGZ file is a CPIO archive compressed with gzip, two layers stacked, gzip over cpio. On macOS, double-click it and Archive Utility extracts it. If a downloaded ZIP turned into a CPGZ, the ZIP is corrupt or incomplete. Re-download it or open it with The Unarchiver instead of double-clicking again.
Programs that open .CPGZ files
| Full name | Gzip-compressed CPIO Archive |
|---|---|
| Developer | N/A (combination of POSIX cpio + GNU gzip; produced by macOS ditto/Archive Utility) |
| First released | cpio: 1970s Unix; gzip: 1992. The .cpgz pairing is a macOS convention. |
| Category | Archives |
| MIME type | application/gzip |
| Signature | 1F 8B 08 0x1F 0x8B 0x08 - gzip header (outer layer); decompresses to a cpio archive |
Related viewers
Found something inside the archive? Open it here.
Do I have to unpack the whole .CPGZ file?
No. The viewer reads its table of contents first and only unpacks a file when you click it. That works even with multi-gigabyte archives, because we read just the bytes we need.
Can I open password-protected archives?
Yes, for ZIP (ZipCrypto and AES) and 7Z. You'll be asked for the password,. We can't recover forgotten passwords.
Is my .CPGZ file uploaded anywhere?
No. The code that unpacks the file is downloaded once and then reused.
Why does a .docx or .apk open as an archive?
Because they are ZIP archives under the hood. Office documents, Android apps, Java programs and EPUB books all use ZIP as their container.
What about split archives (.001, .z01, .part1.rar)?
Multi-part archives need all their parts. Today you can open the first part to see the file list; joining parts is on our roadmap.
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