1DR File

What are 1DR files and how to open them

Are you having problems opening a 1DR file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your 1DR files.

What is a 1DR file?

A .1DR file is a 1dir+ Directory Tree Info file.

1dir+ Directory Tree Info files store a snapshot of directory structure metadata, typically generated by the file identification tool TrID for describing the layouts of file systems or folders. They are not documents themselves but information catalogs listing what files/folders are contained in a particular directory tree. These files help tools compare or identify directory contents statistically rather than preserve actual file data.

These files are produced by TrID itself when it analyzes directory trees, using them to match layouts or detect known patterns. Users and software that perform pattern recognition - such as malware detectors or classification systems - read the structure information preserved in .1DR files. Data in them can include paths, folder nesting, presence or absence of files, sizes, but they do not contain the file contents.

Files of this type begin with the ASCII text signature "1dir+Tree" starting at byte offset zero, then at offset 12 has a byte 0x2E, and at offset 14 a byte 0x1A. This header uniquely identifies the format for parsing tools.

How to open 1DR files

Important: Different programs may use files with the 1DR file extension for different purposes, so unless you are sure which format your 1DR file is, you may need to try a few different programs.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Last updated: August 14, 2026

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