What is the GI file format?
.gi is a disc image file format produced by the Prassi Global Image burning suite, later marketed as RecordNow under Veritas, Sonic Solutions, and Roxio. It stores a sector-by-sector binary copy of a CD or DVD, with a small proprietary header preceding the raw sector data; the payload usually embeds an ISO 9660 or UDF filesystem. .gi files can be mounted as virtual disks and accessed like normal discs. They can also be used to create optical data discs. The format is associated primarily with the Roxio Creator/RecordNow toolchain but is supported by several disc-image and virtual drive tools. The .gi standard is proprietary and not publicly documented, and the software that originated it has long been discontinued - making it a niche, seldom-used format today.
Creating a disc image from a copyrighted disc is not considered a breach of copyright or license agreement, provided that the user has access to the original media disc. Creating virtual disks allows the user to access data that would otherwise require a CD/DVD drive attached to the computer, and is a common solution for extending the lifetime of an optical disc or speeding up software installation. Because RecordNow and PrimoDVD are no longer actively developed, working with an existing .gi file typically means burning it back to disc with a compatible tool such as ImgBurn or IsoBuster, or attempting to treat it as a raw sector image - similar to a BIN file - and extracting its contents.
Security & safety
RISK: MEDIUMA .gi disc image is passive data, but it can contain anything the original disc held, including autorun-based malware on old software/game discs. Scan extracted contents before running installers, and be cautious mounting images from untrusted sources. Separately, avoid sketchy 'GI file opener' downloads - use the established disc tools listed here; some search-driven 'universal openers' are adware/PUP.
Format details
in a nutshell- Genuine Fractals / image-editing intermediate - A handful of imaging tools used .gi for proprietary intermediate image data - unrelated to disc images.
- Game / engine index files - Some games and tools used .gi for internal index or global-illumination cache data (e.g. lighting bake caches).
Programs that open GI files
Windows5 apps
ImgBurn
Free Use 'Write image file to disc' to burn the .gi (or a converted .iso) back to a blank CD/DVD. 
UltraISO
Paid File → Open the .gi, then extract files, mount the virtual drive, or burn it back to a disc. 
IsoBuster
Freemium Open the .gi as a disc image; browse the embedded ISO9660/UDF filesystem and extract files even from odd/partial images. 
Technical details
deep spec| Format type | Optical disc (CD/DVD) sector-by-sector binary image |
| Developer | Prassi / Veritas / Sonic Solutions / Roxio (RecordNow / PrimoDVD lineage) |
| Encoding | Binary (raw sectors) |
| Byte order | Little-endian |
| File structure | Proprietary Global Image header followed by a raw sector-by-sector dump of the source CD or DVD |
| Sector sizes | 2048 bytes (Mode 1 data) or 2352 bytes (raw / audio tracks) |
| Embedded filesystem | ISO 9660 or UDF, inherited from the source disc |
| Compression | None - raw sector dump, uncompressed |
| Typical file size | Up to ~700 MB (CD) or ~4.7 GB / ~8.5 GB (single- / dual-layer DVD) |
| Magic byte detection | No stable public magic number; tools locate the embedded ISO 9660 volume descriptor (string CD001) inside the sector payload to identify the image |
| Associated OS | Windows |
| MIME type | application/octet-stream (unofficial: application/x-gi) |
| Format status | Frozen / effectively discontinued; RecordNow and PrimoDVD are no longer actively developed |
| Filename capacity | Bound by the embedded ISO 9660 or UDF filesystem limits of the source disc |
| Released | Late 1990s-early 2000s (Prassi PrimoDVD / RecordNow burning suite) |
| Latest version | Tied to RecordNow / PrimoDVD versions; format effectively frozen (software discontinued) |
GI conversions
Community Q&A
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