What Is UDF Mode in Nero DVD?

By James Highland

A particularly versatile development in modern computing has been the ease and flexibility of copying a wide variety of data formats onto media with large storage capacities. The prevalence of DVD burning capabilities on most computers has escalated the many uses of this technology, from storing photos and other files, to making music and video discs ready for any player. Nero software presents options for creating DVDs in various file formats, including the Universal Disc Format (UDF). An understanding of this format helps users decide if UDF is appropriate for the DVD they are making.


Prior to the widespread use of DVD recordable media, the similar CD format was in use for many years. All stored files on a computer system must follow a specific file format, and this applies to removable media as well. The CD technology popularized the ISO 9660 file structure, which became a standard and allowed CDs created from almost any source to be compatible with any CD player or drive. However, ISO 9660 has limitations that make it less effective for the many new uses for DVD media.

Optical Storage Technology Association

The Optical Storage Technology Association (OSTA) sought to replace the aging ISO 9660 standard with a more versatile file structure capable of handling the applications of large-capacity media such as DVDs. Since CDs cannot effectively store long video files and extensive data archives, the ISO 9660 format did not translate well for DVD media. Thus, the UDF was born to alleviate these deficiencies and to maximize the portability of this new storage format for a variety of hardware types, ushering in a new standard in data storage.


The ISO 9660 was a gradual development only after numerous design changes in CD file formats frustrated manufacturers over many years as new uses for the CD were developed. Thus, a central need in the development of DVD technology was the standardization of file formats regardless of DVD content. Storage media may contain files, music, video, photos or any combination of these and more, presented on a disc designed for a computer, a stand-alone DVD player or both. The UDF format was initiated at the beginning of the DVD revolution to immediately ensure that discs were as portable as possible.

UDF Bridge

Since older DVD drives and players may not recognize the UDF format, a special process was implemented to ensure that these devices could also recognize DVD data. The UDF Bridge format was primarily used in the late 1990s and creates DVD discs with both UDF and ISO 9660 formats. However, certain uses of DVD media, including DVD-ROM (read only) discs, are typically still created with this format today, to ensure playback on older computers. Other DVD formats, such as those for video, exclusively use UDF only.


Nero is capable of creating ISO 9660, UDF and UDF Bridge file formats for DVDs. As a general rule, UDF is the recommended format because it is more commonly recognized among DVD drives and players. However, if the created DVD may be used on much older computers, UDF Bridge is a consideration. In rare cases, an ISO 9660 DVD may be created if the disc is for use on Windows 95 computers and older.

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