DROID is a file format identification tool, which can process single or batched digital objects to determine their file type, size, age, and change history. DROID can currently identify over 250 file formats, with more formats being added regularly.


The National Archives of the United Kingdom

Licensing and cost

BSD Licensefree.

Development activity

DROID 6.1.2 was released in June 2013, while signature file 68 was released in May 2013.

The tool is advertised as an element of the National Archive's current Digital Continuity Service, and as such is actively supported. Plans for future development are available at http://droid7.wikispaces.com/.

Platform and interoperability

DROID is a platform-independent Java application; versions up to 6.1 required a Runtime Environment (JRE) of 1.6, while more recent versions also run on JRE 1.7 (Java 7). It includes a public API to allow integration with other systems.

Profiles created using earlier earlier versions of DROID will not work with DROID 6.0.

Functional notes

DROID identifies files by checking against both internal and external signatures. These signatures are gathered from information recorded in the PRONOM technical registry, which is updated regularly.  It is therefore important that the user routinely download these updates.  DROID advertises that it can be configured to automatically download the updated signature files, but it should be noted that this is a special configuration and not the default.

DROID was developed as a format identifier, and so its actual metadata output is limited.

Documentation and user support

Excellent documentation is available through both the DROID Sourceforge and the National Archives websites, including a general user guide, a guide to the command-line interface, and a demonstration video

User support is available through an active Google Group. Issues can be reported at the GitHub Issue Tracker. In addition, the Digital Continuity Service of the National Archive gives contact information for questions and concerns.


The DROID download package includes a Windows Installation Wizard, which creates an easier experience. During use, it can be invoked from two interfaces: both a Java Swing GUI and a command line interface.

Expertise required

Users should have a solid grounding in the issues related to preservation of file formats. Configuration also benefits from knowledge of APIs.

Standards compliance

DROID uses information from the PRONOM file format registry to analyse the digital objects.

Influence and take-up

Sourceforge statistics (relating to versions up to 6.01) indicate nearly 22,500 downloads.

DROID is incorporated into a number of other preservation tools, including JHOVE2 and FITS.

Last reviewed: 
8 July, 2013