Free online TAR to ISO converter

A disc-authoring program, virtual optical drive, installer, or device may require an ISO image instead of a TAR archive. The conversion either rebuilds an ISO from the archive's extracted files or places the unchanged TAR file inside an ISO; these produce different results.

What the TAR format is

TAR, short for Tape Archive, stores multiple files and directories in one sequential container. Unix and Linux backup tools, source-code distributors, package builders, and command-line workflows commonly use .tar files.

A plain .tar file is not compressed. .tar.gz, .tgz, .tar.bz2, and .tar.xz combine TAR with gzip, bzip2, or xz compression. TAR can record paths, permissions, ownership, symbolic links, hard links, and timestamps, but it does not define an optical-disc filesystem, boot catalog, partition table, or original disc sectors.

What the ISO format is

An ISO is an image of optical-disc data, usually containing an ISO 9660 filesystem with optional Joliet or Rock Ridge extensions, or a UDF filesystem. Operating systems can mount it as a virtual CD or DVD, and disc-authoring software can write it to optical media.

ISO 9660 provides broad compatibility but restricts filenames and metadata. Joliet improves Windows filename support; Rock Ridge represents Unix-oriented names, permissions, timestamps, and symbolic links; UDF supports newer optical-media layouts and large files. An ISO created from a directory is normally read-only after creation and is not automatically bootable.

Build an ISO from the extracted contents

This is the usual method when opening the ISO should show the files that were inside the TAR. It creates a new filesystem image rather than performing a sector-for-sector conversion.

1. Extract the archive into a temporary staging directory. Inspect untrusted archives before extraction and do not extract them directly into a system directory.

mkdir iso-root
# Plain TAR
tar -xf archive.tar -C iso-root
# gzip-compressed TAR
tar -xzf archive.tar.gz -C iso-root
# xz-compressed TAR
tar -xJf archive.tar.xz -C iso-root

Use a TAR implementation that supports the compression method; GNU tar usually detects compression with -xf, but explicit options are more portable. If the archive contains one top-level directory, that directory remains at the ISO root unless you move its contents into iso-root.

2. Install xorriso from the Linux package manager or with Homebrew on macOS, then create the image:

xorriso -as mkisofs -r -J -iso-level 3 -V ARCHIVE -o output.iso iso-root/.

-r adds Rock Ridge metadata, -J adds Joliet names, -iso-level 3 permits larger files than strict ISO 9660 levels, -V sets the volume label, and -o selects the output file. The iso-root/. source places the extracted contents at the ISO root instead of adding an iso-root directory.

3. Inspect and mount the result before distributing or burning it:

xorriso -indev output.iso -ls /

On Linux, isoinfo -i output.iso -f can list files. Open representative files after mounting when content integrity matters.

Put the TAR file itself inside an ISO

Use this form when the archive must remain one unchanged file but a receiving program accepts only an ISO container:

xorriso -as mkisofs -r -J -V ARCHIVE -o output.iso archive.tar

For a compressed archive, replace archive.tar with its actual filename. The resulting ISO contains archive.tar; it does not make the TAR contents directly visible as the ISO's directory tree.

Windows desktop method

1. Use 7-Zip to extract the TAR or compressed TAR into a new folder.
2. In AnyBurn, choose Create image file from files/folders, add the extracted folder or its contents, select ISO output, choose a destination such as output.iso, and create the image.
3. Mount the ISO in File Explorer and check the directory structure and important files.

Other installed ISO authoring applications provide an equivalent Create image from files or folders function. The resulting data ISO is not bootable unless the authoring operation includes a compatible boot image and boot catalog.

Convert without installing software

The TAR can be converted on 101convert.com for free by uploading the file, selecting ISO as the output, starting the conversion, and downloading the result. Do not upload confidential backups, credentials, private source code, or other sensitive data to a service that receives the archive contents.

Compatibility and quality limits

• Renaming does not convert the file. Changing .tar to .iso leaves the TAR header and archive structure intact, so ISO software will not find the expected filesystem descriptors.
• The rebuilt ISO is usually uncompressed. Its size depends on the extracted data and ISO filesystem overhead, so a small .tar.gz or .tar.xz can produce a much larger image.
• Extraction and rebuilding do not preserve the original TAR byte stream, archive ordering, compression, or necessarily its exact permissions, ownership, timestamps, hard links, sparse-file layout, extended attributes, and symbolic-link behavior. Windows staging folders commonly lose Unix-specific metadata.
• ISO 9660, Joliet, and UDF have different filename, path, metadata, and file-size limits. Rock Ridge is preferable for Unix-oriented data, while Joliet improves compatibility with Windows; neither preserves every filesystem feature.
• Files in an operating-system tree do not make an image bootable. Bootability requires the correct boot image, catalog, filesystem layout, platform-specific options, and sometimes partition structures. Merely placing boot-related files in the staging directory is insufficient.
• If the TAR was produced by unpacking an existing disc image, rebuilding it cannot reliably restore the original boot sectors, partition table, boot catalog, volume identifiers, session layout, or unused sectors. Keep the original ISO when exact reproduction is required.
• Retain the original TAR alongside the ISO when archive metadata or exact restoration matters; the ISO is a newly authored filesystem image, not a lossless TAR container.