Format at a glance
- Full name
- Optical Disc Image (ISO)
- File extensions
- .iso
- MIME types
- application/octet-stream
- Category
- Archives
- Compression
- Depends on the contained codec
- Transparency
- Not applicable
- Animation
- Not applicable
- Properties
Suitable tools
What is this format?
The name derives from ISO 9660, but .iso files may also contain UDF or hybrid filesystem structures. Boot information and disc layouts can be included.
An ISO image normally preserves data without compression and is therefore often close to the occupied size of the original disc. Additional packaging is required for compression.
What is it used for?
- Distribution of bootable operating-system media
- Software and installation discs
- Archiving optical media
- Images for virtual machines
Which programs can open it?
- Windows File Explorer
- macOS Disk Utility
- Linux mount, GNOME Disks and KDE tools
- 7-Zip for reading individual files
Support across devices and browsers
Windows handles ISO either natively or through archive tools such as 7-Zip.
Finder, Disk Utility or applications such as Keka open suitable ISO files on macOS.
Linux provides command-line and desktop tools for ISO; exact read and write support depends on the format.
File managers and archive apps may open ISO, but support differs between applications.
Files handles some archives natively; ISO may require a separate application.
Browsers do not display ISO as a document. LocalFileLab uses local WebAssembly for supported operations.
Advantages
- Preserves disc structure in one file
- Can be mounted as a virtual drive
- Suitable for bootable media
Disadvantages
- Usually has no built-in compression
- Changes often require a new image
- Not every ISO uses the same filesystem or boot layout
Comparison with alternatives
ZIP compresses individual files; ISO represents a disc and its filesystem structure.
DMG is Apple's flexible disk-image format and may use extra compression or encryption.
7Z focuses on file compression and does not preserve a bootable optical-disc layout.
LocalFileLab support
ISO is recognized as an input. Archive structure and contained files are processed locally.
ISO is not currently a verified LocalFileLab output.
LocalFileLab can compress ISO locally or package it in a supported archive; already compressed content will not necessarily become smaller.
A complete ISO preview is not currently available.
Complete preservation of format-specific metadata is not guaranteed.
Related formats
Frequently asked questions
Must an ISO file be burned?
No. Modern systems can usually mount ISO files as virtual drives; some devices still require USB or optical media.
Is ISO a compressed format?
Usually not. An ISO represents the content and can then be packaged in ZIP, 7Z or another archive.
Can LocalFileLab create ISO files?
ISO is currently intended as an input or for packaging into another archive, not as a verified ISO output.