# CPIO Viewer

Free online CPIO viewer. Open CPIO archives (.cpio) in your browser to list contents — no upload, no extraction.

> Canonical page: https://elysiatools.com/en/viewers/cpio

- **Category:** Archives

- **Supported formats:** .cpio

## Overview

This CPIO viewer reads CPIO archives directly in your browser. CPIO (.cpio) is a Unix archive format similar to TAR, historically used for backups, RPM packages and Linux initramfs images. Pick a sample or choose your own .cpio file to browse its contents instantly, with no upload.

## When to use

- You received a .cpio file and want to inspect it without extracting.
- You need a private preview of a Linux initramfs or RPM payload.
- You want to check a CPIO archive on a machine without cpio tools.

## How it works

- Select a built-in sample archive or choose your own .cpio file.
- The viewer reads the archive's contents in your browser — nothing is uploaded.
- Browse the file list to see embedded files and metadata.

## Use cases

- Inspecting Linux initramfs images.
- Checking RPM package payloads.
- Examining legacy Unix backup archives.

## Samples

- **Sample Archive**: A CPIO archive sample for in-browser preview

## Frequently asked questions

### What is a CPIO file?

CPIO (.cpio, copy in/out) is a Unix archive format that bundles files into a single stream, similar to TAR. It supports multiple binary and ASCII formats and is used in RPM packages and Linux initramfs images.

### Are my CPIO files uploaded?

No. Files you open from your device stay on your device and are read locally. Only the public sample archive is requested from the server.

### What is the difference between CPIO and TAR?

Both are Unix archive formats. CPIO supports several formats (binary, ASCII newc, CRC) and is used in RPM and initramfs. TAR is more common for general file distribution. Both bundle files without compression.

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