Open CPIO files in your browser
One of the oldest Unix archives, still at work deep inside Linux. Open a cpio right here, see every file and open the ones you need. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your archive opens like a folder, its files listed on the left.
- Listed like a folder • Unpacks only what you pick
- Locked archives • Hidden file names included
- Search • Find any file by its name
- Export • Save as ZIP or Extract all
About CPIO
Dick Haight wrote cpio at AT&T, and it appeared in 1977 in PWB/UNIX, two years before tar. Its name comes from copy in and copy out, the two ways it moves files into and out of an archive.
Linux still uses it: RPM packages carry their files in a compressed cpio archive, and the initramfs that starts Linux at boot is one too. Like TAR, it strings files together with their folders and permissions, and compresses nothing.
No browser opens cpio by itself. Filepeek reads it with 7-Zip compiled to WebAssembly, lists its files like a folder and opens the one you pick, and Save as ZIP turns it into a ZIP that any computer opens.
CPIO archive
.cpio
Format
- MIME type
- application/x-cpio
- Made by
- Dick Haight at AT&T
- Released
- 1977
Inside the file
- Compression
- None of its own
- Holds
- Files, folders and permissions
- Kinds
- Binary, odc and newc
- Found in
- RPM packages and initramfs
Opens in every browser
No browser opens cpio by itself. Filepeek lists and unpacks it with 7-Zip in Chrome, Edge, Firefox and Safari.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Questions
How do I open a CPIO file?
Drop it on this page or choose Peek a CPIO. Its files are listed like a folder, and the one you pick opens right away, with no command line.
What's the difference between cpio and TAR?
Both string files together without compressing them. TAR became the more common one, while cpio lives on inside RPM packages and the Linux initramfs.
Can I read the scripts and configs inside?
Yes. Scripts, configs and other texts open in the text viewer, with line numbers and search.
Can I turn it into a ZIP?
Yes. Choose Export, then Save as ZIP. Phones and computers open the ZIP without an app.
Is my file uploaded?
No. The archive is read inside your browser and never leaves your device. Nothing in it runs.