DAT File

What are DAT files and how to open them

Are you having problems opening a DAT 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 DAT files.

What is a DAT file?

DAT files have multiple uses, and Outlook Email in Rich Text Format (winmail.dat) is one of them. Read more about the other uses further down the page.

Outlook Email in Rich Text Format (winmail.dat)

Sometimes you may receive an email attachment named winmail.dat and wonder what that is. You see it because the sender of the message used the Microsoft Outlook email client and sent the email in Rich Text Format, a format that allows different font sizes and colors.

Not all email clients understand this format, and in this case, the Rich Text formatted email message ends up as a winmail.dat file attached to the email.

Technically these files are called TNEF files, short for Transport Neutral Encapsulation Format, which is the name Microsoft used for the file format.

There are various stand-alone viewers available if your email client does not support winmail.dat files.

How to open DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

Programs that open Outlook Email in Rich Text Format (winmail.dat) files

Last updated: January 25, 2025

All known file formats using extension .DAT

While Outlook Email in Rich Text Format (winmail.dat) is a popular type of DAT-file, we know of 67 different uses of the .DAT file extension. Different software may use files with the same extension for different types of data.

Windows Registry Hive

Microsoft Windows uses a concept called the Windows Registry to store various configuration settings that affect how Windows and installed software works. The registry values are stored in different registry files, called Registry Hives. For example, the Registry holds information about which application you have selected to be the default opener for JPEG images.

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!

Bitcoin data

The original Bitcoin client stores private key information in a file named wallet.dat. This file contains your private keys, public keys, the transactions related to your wallet, and other important data. If you have an HD wallet, it also includes the HD seed and the private key's derivation paths. Keep this file safe, as it contains your bitcoins.

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!

LabVIEW Binary Data Log

LabVIEW provides an easy-to-use application development environment designed specifically for the needs of engineers and scientists. Without any prior programming experience, you can use LabVIEW to take measurements from various devices and create custom software functionality.

Data captured by your application can be logged to files in various formats using built-in functions. The DAT format is more compact than a user-readable text format and can contain various data, e.g., temperature readings.

DAT opener for Windows

We have identified one DAT opener that is compatible with this specific type of DAT file.

Surface-water Modeling System Dataset

The Surface-water Modeling System Dataset (with the .DAT extension) files are a type of data file. They're specifically used within the field of hydrodynamics, which means they help study how water behaves when it moves.

These .DAT files are typically used with a software tool called Surface-water Modeling System (SMS). Experts in the field of water studies - like hydrologists and aquatic scientists - use SMS to make sense of complex datasets about water flow and to map them out visually.

Imagine a scenario where you need to know how water will behave under certain conditions, like which direction it will flow if a dam breaks or how it will flow around a new bridge. That's exactly what this software and the .DAT files are used for.

Of course, the exact contents of a .DAT file can vary because they depend on what measurements have been taken. Generally, though, they contain information about things like water speed, depth, and direction.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

MicroStation Resource data

MicroStation is a Computer-Aided Design (CAD) software used in the architectural and engineering industries to design structures and products in 2D and 3D. A resource is an element that can be used in such a drawing project.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

Clarion 2 Database

This file contains the data users have entered into a program developed in the Clarion programming language. Clarion is a development environment focused on creating database applications. Therefore, the database file is not used by Clarion itself, but one of the hundreds of programs developed using this programming language. Some viewers can display the content of any Clarion generated database, as the database format itself is standardized.

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!

Runtime Software Compressed Disk Image

DriveImage from Runtime Software is used to create copies of an entire hard drive partition. A drive copy is saved as an XML file accompanied by a DAT file, and optionally a series of files named 001, 002, 003, etc., if you have selected to split the copy into multiple files of smaller size.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

CHEMICAL Molecule Data

CHEMICAL is a molecular modeling program for MS-DOS by Larry Puhl that bonds and places atoms that the user has selected from a Periodic Table. Its associated data files contain molecular data models.

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!

Adobe Freehand Project

Freehand was a vector drawing program for Windows and Mac from Adobe, which acquired it from Macromedia. At the time, it was a market leader in vector drawing programs. The DAT file created by this program was a vector drawing project file.

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!

Clrmamepro DAT / MAME Listinfo ROM info

This type of dat file contains information about an arcade machine ROM copy. The files contain, e.g., name of the game, manufacturer, size, checksums etc. The checksums can be used to verify that your copy of the ROM is complete and unaltered.

MAME is a Multi Arcade Machine Emulator that can run old arcade games on your computer.

Programs that open these DAT files

We have identified 2 DAT openers that are compatible with this specific type of DAT file.

DirTel Database

DirTel is an address book for MS-DOS, and the associated DAT file contains the addresses entered by the user.

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!

PasswordBox Encrypted Database

PasswordBox is a console-mode program that will keep all your passwords safe in an encrypted database protected by a master password. The database consists of a single .dat file.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

DVD Master Disc Control File

DDVID.DAT is one of several control files written to the area reserved for mastering content on a Master DVD to prepare pressing duplicates.

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!

GeoLite1 IP geolocation database

GeoLocation database from Maxmind. It contains mappings between IP-addresses and physical locations, so you can use a user's IP address to look up the user's country. Home pages often use it to enable specific behavior when a website visitor is from a specific country - e.g. block access, change language, or change currency.

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!

InnoSetup Uninstall Log

InnoSetup is a Windows installation program used by developers to create installation packages of their software. The uninstall log files contain information about which files must be removed if you decide to uninstall a software program.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

CardFile PIM data

Data file for the legacy Personal Information Manager software, CardFile PIM, for the Atari home computers.

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!

EasyRecovery saved recovery state

EasyRecovery from OnTrack is a software tool to recover data from crashed hard drives and solid-state disks. During the recovery process, it saves a state file so it knows which sections of the drive have been processed so far.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

Linux Kernel X86 Bootable

A Linux kernel is the "brain" of a Linux system. It is the main Linux operating system file that provides the low-level functions of the operating system.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

LocoScript Data

LocoScript was a word processor first developed for the Amstrad CPC 464 home computer in the late 1980s. Later, versions were made for MS-DOS. Documents saved by LocoScript used the .dat file extension.

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!

Compass MSX-Assembler Data

We know that one DAT format is Compass MSX-Assembler Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Compressed Data

We know that one DAT format is Compressed Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Createc SPM Data

We know that one DAT format is Createc SPM Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

DKBtrace Scene

We know that one DAT format is DKBtrace Scene. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Gaze Configuration

Gaze is a DOS-based graphical menu program by J. Schipperheijn. It provides a visual interface for tasks that are usually typed as commands.

Gaze .dat files store color configurations, menu item references, and other environment parameters. The program loads these details to display and handle menus as specified. Adjusting them changes the behavior of menu items and overall layout.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

HOLEN BIOS+CMOS Dump

We know that one DAT format is HOLEN BIOS+CMOS Dump. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

HPFS-Access DB

We know that one DAT format is HPFS-Access DB. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

IL2CPP Global Metadata

The IL2CPP Global Metadata file format is a unique file format used in Unity, a popular game development platform. It's like a recipe book for the game or application, containing the essential information defining how everything within the game works together.

IL2CPP stands for 'Intermediate Language To C++'. Any game built and published with Unity using IL2CPP technology will have this DAT file. It acts as a sort of translator, helping to convert the original game coding language into a language that's more efficient for the game's runtime operation, which is C++.

This DAT file contains global metadata, meaning it holds important 'global' or system-wide data about the game or app, like code structures, references, and other crucial information. All this information aids in optimizing the game's performance, making it run smoothly and efficiently, regardless of the system or device it's on.

While this file is instrumental in the functioning of the game, as a user you'll often never see it or need to interact with it directly. It's predominantly there for the game developers to help them create the best experience possible. So, in simple terms, you can imagine the DAT file as an instruction manual, filled with vital details about the game. It helps Unity translate the developer's creative vision into an actual game that you can play, and ensures that it runs optimally across different systems and devices.

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!

INSTALL Professional Project

These files contain project settings for the DOS program INSTALL Professional.

INSTALL Professional was a script-driven installation program designed for software developers distributing products on MS-DOS. Its primary goal was to make installing software as seamless as possible, even for novice users. By automating tasks like creating directories, copying files, and handling multiple disks, INSTALL Professional saved developers the time and effort of writing their own installation routines from scratch. Its robust error-handling system would detect issues - like a missing disk or a full hard drive - and guide end-users toward fixing them, ensuring that installations were both user-friendly and reliable.

A central feature of INSTALL Professional was its proprietary "Reduce" compression algorithm, used to shrink program files before distribution. This helped developers fit their software onto fewer disks and streamlined the installation process. The program also offered a library manager to combine multiple compressed files into a single archive and quickly "freshen" or update files when releasing new versions. This was particularly helpful for large-scale distribution, where managing many files across multiple disks or CD-ROMs could easily become cumbersome.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

Knowledge Dynamics Installer Project

We know that one DAT format is Knowledge Dynamics Installer Project. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Konpass MSX-Assembler Data

We know that one DAT format is Konpass MSX-Assembler Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

MADE Engine DB

We know that one DAT format is MADE Engine DB. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Made4U Remote Codes Db / Programming Data

We know that one DAT format is Made4U Remote Codes Db / Programming Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

McAfee VirusScan Data

We know that one DAT format is McAfee VirusScan Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Micrografx Graph Data

We know that one DAT format is Micrografx Graph Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Microsoft Internet Explorer cache

The Internet Explorer web browser stores certain data on your PC to speed up the display of web pages. For example, if you revisit the same page, the web browser will only need to download the changed content and not, e.g., fonts and images that have not changed. This saves both bandwidth and time.

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!

MirandaIM database

Miranda IM was an instant messenger application for Windows with support for multiple messaging protocols. You could chat on ICQ, IRC, AOL, and many other platforms using this single application.

The database file contains the log/history of all your chats.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

Music Assistant Scale

We know that one DAT format is Music Assistant Scale. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

NetShield Virus Patterns

We know that one DAT format is NetShield Virus Patterns. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Network Associates VirusScan Data

We know that one DAT format is Network Associates VirusScan Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Novell Librarian Data

We know that one DAT format is Novell Librarian Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Palm Desktop DateBook

Calendar database file used by Palm desktop software, a companion software for Palm Pilot handheld devices. This file contains a user's calendar entries and repeating events.

Programs that open these DAT files

We have identified one DAT opener that is compatible with this specific type of DAT file.

PCBoard Config Data

We know that one DAT format is PCBoard Config Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

RepiPack Archive

We know that one DAT format is RepiPack Archive. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

RIKA Firenet Firmware

We know that one DAT format is RIKA Firenet Firmware. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Sea Graphics Viewer Data

We know that one DAT format is Sea Graphics Viewer Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

SimRefinery Scenario

We know that one DAT format is SimRefinery Scenario. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

SoftAction Resource Data

We know that one DAT format is SoftAction Resource Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Softdesk AdCADD Data

We know that one DAT format is Softdesk AdCADD Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

SoftICE Initialization Data

We know that one DAT format is SoftICE Initialization Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Sound Images Sound Driver

We know that one DAT format is Sound Images Sound Driver. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Spectre 3D Model/texture Data

We know that one DAT format is Spectre 3D Model/texture Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

StarCalc Data

We know that one DAT format is StarCalc Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

StarForce protected data

StarForce is a copy protection system. It stores one or more files in a single "container" that gets protected by their proprietary system. Software developers embed part of the StarForce protection into their application, enabling it to read the data from the protected container file if the user has entered the correct license key. Without the key, the protected data cannot be read.

You usually do not need to edit or view these files, as they only contain information usable by the software program that uses them.

Stowaway Archive

We know that one DAT format is Stowaway Archive. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

The Chessmaster Game Data

We know that one DAT format is The Chessmaster Game Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

The Norton AntiVirus Virus Signatures

We know that one DAT format is The Norton AntiVirus Virus Signatures. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

The Software Toolworks' Hyperbase Data

We know that one DAT format is The Software Toolworks' Hyperbase Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

TouchBase Contacts DB

We know that one DAT format is TouchBase Contacts DB. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Track Attack Track Data

We know that one DAT format is Track Attack Track Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

TurboActivate Licensing Info

We know that one DAT format is TurboActivate Licensing Info. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Uropa2 Operation Data

We know that one DAT format is Uropa2 Operation Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

VideoCD MPEG

MPEG encoded video stream in a RIFF container used in VideoCDs.

Programs that open these DAT files

We have identified 2 DAT openers that are compatible with this specific type of DAT file.

Windows boot log data

When a Windows PC starts (boots), Windows will log data about the boot process to a log file. This file will help resolve startup problems as the administrator will be able to see how far in the startup process Windows came before a problem occurred.

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!

Yu Gi Oh! Data

We know that one DAT format is Yu Gi Oh! Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Zulu BPM Library

We know that one DAT format is Zulu BPM Library. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

Zygo MetroPro SPM Data

We know that one DAT format is Zygo MetroPro SPM Data. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

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!

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