NRG (Nero CD Image) file format

.nrg · disk image · introduced 1997 by Nero AG

What is a NRG (Nero CD Image) file?

NRG is Nero Burning ROM's native CD/DVD image format. It is essentially a raw sector dump with Nero-specific metadata describing tracks, sessions, and audio CD layout. nrg2iso converts simple data NRGs to plain ISO; mixed-mode and audio NRGs require Nero or PowerISO.

Most readers reach this page after double-clicking a .nrg file and finding their operating system unsure what to do with it. The good news: NRG (Nero CD Image) is a well-understood format with mature tooling on every major platform. It is supported in one click by mainstream archivers on Windows, macOS, and Linux.

How to extract a NRG (Nero CD Image) file

Opening a .nrg file is straightforward on every modern operating system. The exact steps depend on which platform you are on:

On Windows

Locate the .nrg file in File Explorer.
Right-click the file. If you have 7-Zip installed, choose 7-Zip → Extract Here. On Windows 11 the built-in extractor handles ZIP, 7z, RAR and several other formats directly through Extract All…
If prompted, pick a destination folder and click Extract.
The extracted files appear in a folder next to the original archive.

On macOS

Find the .nrg file in Finder.
Install The Unarchiver from the Mac App Store, or Keka for both creating and extracting.
Right-click the file → Open With → The Unarchiver (or just double-click after Unarchiver is set as the default).
The extracted folder appears next to the archive.

On Linux

Use your file manager: right-click the archive → Extract Here (file-roller on GNOME, Ark on KDE).

On the command line, run one of:

7z x archive.nrg    # works for almost any format

The files appear in the current directory.

How to create a NRG (Nero CD Image) file

To pack files into a .nrg archive, you typically need an archiver that supports writing this format. Not every tool can create every format — for example, only WinRAR can create real RAR files. The sidebar lists the software known to read and write NRG (Nero CD Image).

On the command line, the canonical create command is:

# Use 7-Zip, PeaZip, or the format's reference tool to create .nrg files.

If you regularly create archives at scale, a dedicated archive automation suite can wrap this command in scheduled jobs, integrity checks, and offsite replication.

Strengths

Preserves multi-session and audio metadata
Burns back perfectly with Nero

Weaknesses and limitations

Proprietary
Limited non-Nero tooling

Typical use cases

Backups burned with Nero
Audio CD images preserving track gaps

Technical details

NRG (Nero CD Image) uses the None (raw sectors + Nero metadata) algorithm and is identified on disk by the magic byte sequence NER5 (offset varies). The standard MIME type is application/x-nero-nrg. The format is a proprietary specification and is subject to license restrictions for some uses (notably creation).

Frequently asked questions

Is NRG (Nero CD Image) safe to open?

Archive files are containers — they are only as safe as what they contain. A .nrg from a trusted source is fine; one received from a stranger can hold malicious executables, scripts, or files engineered to exploit bugs in your archiver. Always keep your archiver updated, and never run unknown executables that come out of an archive. A safe workflow is to extract into a sandbox and scan the contents before opening anything.

What is the maximum file size?

Modern implementations support archives in the multi-terabyte range. The practical limit is your filesystem (FAT32 caps at 4 GB; ext4, NTFS, APFS, and exFAT all comfortably handle multi-TB files).

Can I password-protect a NRG (Nero CD Image)?

Some archivers can wrap NRG (Nero CD Image) files in an encrypted container, but the format itself does not always include built-in encryption. Check your archiver's documentation.

How does NRG (Nero CD Image) compare to other formats?

See our format comparison pages such as ZIP vs 7z, ZIP vs RAR, and tar.gz vs tar.xz for side-by-side feature tables.