What Is a DAT File? And How to Open It (With Steps and FAQs)

By Indeed Editorial Team

Published 5 May 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

When you download a computer program or software, you may see it create a range of different file types on your computer. One of the common file types you may find is a DAT file. If you use a computer extensively during your work, learning more about data files can help you read or view them easily. In this article, we discuss what DAT files are, explain how to open and read them on different operating systems and provide answers to some commonly asked questions about these files.

What is a DAT file?

A DAT file, also known as a data file, is a generic data file with the extension .dat. You can usually find a data file after downloading computer software and programs. Data files exist to support the functions of these programs, and are generally not for the users to open and read manually.

Data files often contain plain or binary text, though you may also find videos and music files inside sometimes. You might find data files in application folders or as attachments from email servers. These files might also accompany other files for configuration, such as a dynamic link library file, which is a type of file that contains data, code or resources needed for the running of applications.

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How to open files with a .dat extension on macOS systems

Here are the steps of how to open files with a .dat extension on macOS systems:

1. Find your data files

Data files are more difficult to locate than other types of files. As these files often accompany program files, you can't find them in the "Download" or "Recent" folder. To locate the file, you can open "Finder" and go to the "Application" section. Then, right-click on the application you want to work on to view the drop-down menu and click "Show Package Contents". You may be able to see some files with a .dat extension here.

2. Use TextEdit

After you locate the file you want to open, right-click on it and check the pop-up menu for the files. Then, you can hover over the open "Open With" to view a list of programs with which you can open the selected file. Find an application called TextEdit there. TextEdit is a built-in word processor and text editor on macOS systems that can read most text-based files. Since most files with .dat extension are either binary or plain text, you can read the file with this built-in word processor.

If TextEdit can't open the selected files, it means that the files are not text-based. You may move on to the next step.

3. Use relevant program

Since there are no standard requirements on what a data file can include, you may not be able to open all data files with TextEdit. Check if the file name suggests what program it may associate with. This may suggest that the file is only readable for a specific program. If this is the case, try to open the data file with the program mentioned.

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How to open files with a .dat extension on a Windows system

Here are a few steps explaining how to open data files on a Windows system:

1. Find the file that you want to open

Search for the file that you want to open from the taskbar. Type the name or the keyword of the document to locate it. You can also type ".dat" in the search box, which allows the system to help you locate all the files with a .dat extension on your computer. You can also open "File Explorer" and select a location from the left pane to the browser. For example, you can select "This PC" to look for files that store there.

2. Open it with Notepad

After you locate the file, open it with Notepad. Similar to TextEdit, Notepad is a built-in basic text editor on the Windows system. Right-click on the file icon, hover over the option "Open with" and select the option "Notepad". If you see a lot of "NUT" references and obscure characters on Notepad, it means that the file you're trying to open doesn't contain plain text. It may be because this file is originally a video or mp3 file. Instead, try to open the file with "Windows Media Player".

How to convert files with a .dat extension?

You can convert data files into word documents or PDF files to improve your efficiency in handling this type of file:

On macOS

If you're using macOS system, do the following:

  1. Open the files in TextEdit.

  2. Right-click "File" on the menu bar located at the top of your screen.

  3. Right-click on the option "Export as PDF" and select where you want to save the exported PDF file.

  4. If you want to convert the file to a Word document instead of a PDF file, you can choose to rename the file directly. Right-click "File" on the menu bar and select "Rename", then change the suffix of the document to .doc or .docx.

On Windows

To convert the file to a Word document, do the following:

  1. Open the document in Word.

  2. When the file is visible in this software, click on the "File" menu and choose "Save As".

  3. Select the new file type that you want the document to convert to. It's most common to save the file in a .doc or .docx file type, but you can also choose to save the file as a PDF if you want to preserve the layout of the document.

FAQs about files with a .dat extension

Here are some answers to frequently asked questions about data files:

Do all programs contain these file types?

Not all programs have data files. Some programs may choose to directly store their data within the program instead of creating an extra file for it. Some may also convert the data, such as images and videos, into ZIP files.

When do you convert the data files?

With files that come through rich text format emails, you might use conversion websites or platforms to help you convert and read the file. You can also convert other data files using these platforms. If you're practising coding, you can open a data file and edit the code to see how changes might affect an application.

Can I convert files with a .dat extension to HTML?

You can convert files with a .dat extension to HTML. The process is the same as how you can convert data files to Word documents. For example, after you open the file in a word processor, you can choose to save the file in another format, such as HTML, XML or CSV.

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How do I know what type of file a DAT is?

The best way to determine the type of data file is to try opening it with different programs. Unlike file extensions, like MP4, where people easily identify it as a video file, data files can contain different types of data. As they're usually text, starting with a text editor can help you identify this quickly. If it doesn't show you anything meaningful, try opening the files with photo viewers, video players and HTML readers.

What is Winmail.dat or ATT0001.dat?

Sometimes, you may receive emails that come with Winmail.dat and ATT0001.dat. These files are usually email attachments sent from a particular mail server. You may also receive them because your mail server wasn't able to convert the email content properly. You can convert these data files using online conversion tools. To do so, follow these steps:

  1. Download the dat. format attachment.

  2. Search for a relevant conversion website online. For example, you can use Winmaildat or Any Conv.

  3. Click on the "Choose File" button on the website. When your system file browser pops up, select the file you want to convert.

  4. Click "Start" to begin the conversion process. It may take a few minutes to complete the process if the selected file is too large.

  5. Check the downloadable files generated by the website from the results page. If you see nothing on the results page, it means that there's no document inside the data file.

What are the differences between DAT and CSV files?

DAT and DSV files are similar to each other because both contain document information. CSV files have simpler structures than data files and they only contain text information. For example, a CSV file may contain a list of clients' addresses and contact numbers. This file type allows users to export and import data more easily than using a DAT file. You can usually open and read a CSV file with spreadsheet software.

Please note that none of the companies, institutions or organisations mentioned in this article are affiliated with Indeed.

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