pronom

PRONOM is a file format registry and identification service used in digital preservation. Maintained by The Open Preservation Foundation, it provides a centralized catalog of file formats with machine-readable records to support format identification, validation, and preservation planning. The registry aims to help institutions determine how to manage, migrate, and preserve digital objects over the long term.

PRONOM originated in the UK national archives and the broader digital preservation community. Over time, stewardship shifted to the Open Preservation Foundation, which coordinates ongoing development and maintenance. The data and records are publicly accessible and widely used by libraries, archives, museums, and other heritage institutions.

Each format record in PRONOM includes a format name and version, MIME type, list of file extensions, and a unique identifier known as a PUID. Records also describe technical characteristics, signature patterns or magic numbers, software support, and preservation notes, including risk indicators and recommended actions. The registry emphasizes interoperability with format identification tools and preservation workflows.

In practice, PRONOM underpins tools and processes that identify file formats, assess obsolescence risk, and guide migrations or other preservation strategies. It is used in workflows for ingest, quality control, and long-term access planning, helping institutions prioritize resources and ensure reinterpretability of digital objects.

Coverage in PRONOM spans a wide range of formats, from common office and multimedia types to specialized archival formats. Updates are released periodically, and contributions come from a community of institutions and vendors. While comprehensive, the registry relies on ongoing curation and may lag behind rapidly released formats, so users often corroborate with additional sources.