DF1 File

What are DF1 files and how to open them

Are you having problems opening a DF1 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 DF1 files.

What is a DF1 file?

A .DF1 file is an Omnis Studio Database file.

Omnis Studio Database (.DF1) is a native datafile format used by the Omnis Studio development environment. It stores structured data - tables, indexes, records, free space tables, and metadata - used by applications built or run in Omnis. Developers working with legacy Omnis data architectures usually see data and File classes mapped directly into these .DF1 files.

These files are created and maintained by Omnis Studio (and earlier by Omnis 7). They may span multiple "segments" if the datafile grows large; each segment is a separate file on disk, with a practical limit of about 256 MB per segment. Segments beyond the first must be added manually in Studio or via datafile commands. Omnis Studio also provides a migration path: .DF1 files can be converted into SQL-based databases such as SQLite or PostgreSQL so that existing legacy data-oriented code continues working.

At a technical level, a .DF1 file begins with identifiable byte sequences near the very start (offset 1) including control codes that mark Omnis Studio's native database format. Specific header bytes, large blocks of zeroes, and internal keywords like "INDEXES" and "SLOTS" are embedded in predictable positions.

How to open DF1 files

We have identified two DF1 openers that are compatible with this specific type of DF1 file.

Programs that open Omnis Studio Database files

Last updated: August 4, 2026

Various apps that use files with this extension

These apps are known to open certain types of DF1 files. Remember, different programs may use DF1 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about DF1 file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.