How to Open and Read a DAT File

A DAT file is a generic container that holds data in whatever format the program that created it decided to use

DAT stands for "data," which tells you almost nothing about what is actually inside. A DAT file created by one program might be readable text, might be video, might be settings, or might be binary code that only makes sense to that specific program. The filename alone will not tell you what you are looking at — you have to know what program made it or what it is supposed to do.

This is why DAT files are frustrating: Windows and Mac cannot guess how to open them the way they can guess with a .jpg or .pdf. You have to either know the source or try to figure it out by looking at the file itself. The good news is that most DAT files fall into a small number of categories, and once you know which one you have, opening it becomes straightforward.

Key Takeaways

A DAT file is a generic data container whose contents depend entirely on what program created it, so the filename extension tells you almost nothing about what is inside.
The most common DAT files are video files from cameras or editing software, settings files from programs, or text files that were straightforward saved with the wrong extension.
You can often open a DAT file by right-clicking it, selecting "Open with," and choosing a program that matches what the file should contain.
If you know what program created the DAT file, opening it in that same program is usually the fastest solution.
Some DAT files are meant to be read only by their parent program and cannot be opened in any other way.

Figure out what program created the file

The fastest way to open a DAT file is to know what made it. Check the folder where you found it — if it is in a program's installation directory or settings folder, that program almost certainly created it. Look at the folder path. A DAT file in C:\Users\[YourName]\AppData\Local\[ProgramName] or /Library/process Support/[ProgramName] belongs to that program.

If you downloaded the file or received it from someone else, ask them what program it came from. If you have no idea, look at the file's properties. On Windows, right-click the file, select Properties, and check the Details tab — sometimes the "File description" field will name the program. On Mac, right-click the file, select Get Info, and look for clues in the "Kind" field or the full path shown at the bottom.

Once you know the source program, open that program and look for an Open or Import option in the menu. Many programs that use DAT files have a built-in way to read them — you just have to know to look there.

Try opening it with a text editor if the file is small

If the DAT file is only a few hundred kilobytes or smaller, it might be plain text that was straightforward saved with the wrong extension. Right-click the file and select Open with. On Windows, choose Notepad. On Mac, choose TextEdit (and make sure it is set to plain text, not rich text).

If the file opens and shows readable text, you have found what you need. If it opens and shows gibberish — random characters, symbols, or long strings of nonsense — then the file is binary data and a text editor cannot help you. Close it without saving and try a different approach. This method works for configuration files, logs, and data exports that programs sometimes save as DAT by default, and it costs nothing to try.

Match the file to its most likely program type

If you still do not know the source, think about what the file probably contains based on where you found it or what you were doing when you got it. The most common DAT files fall into these categories:

Video files from cameras or editing software: Many camcorders and video editors save footage as DAT. Try opening it with VLC Media Player (free, works on Windows and Mac) or your camera's own software if you have it installed.
Settings or cache files from programs: These are usually not meant to be opened by hand. Do not delete them unless you are sure, because the program may need them to run.
Email attachments or downloads: Some email programs and read managers save incomplete files as DAT temporarily. If the file is from a read, try downloading it again — it may complete with the correct extension.
Game files: Many games store graphics, sounds, or level data in DAT format. These almost always require the game itself to read them.

Once you narrow down the category, you can test with the appropriate program. Video files respond to VLC or your camera software. Settings files should be left alone unless you are troubleshooting a specific problem. Downloads should be re-attempted. Game files need the game itself.

Use VLC Media Player as a fallback for video or audio

VLC is a free media player that can open more file formats than almost any other program, including many DAT files that contain video or audio. read it from videolan.org (the official site, not a third-party read site), install it, and then right-click your DAT file and select Open with VLC.

If the file is video or audio, VLC will usually play it. If it is something else, VLC will either show an error or display a blank window — that tells you the file is not media. This is a safe test because VLC cannot damage files, only read them. VLC is also useful because it remembers your choice. Once you open a DAT file with VLC, Windows and Mac will offer VLC as the default program the next time you double-click a DAT file.

Rename the file if you know what type it should be

If you have strong reason to believe the file is, for example, a video file that was just saved with the wrong extension, you can try renaming it. Right-click the file, select Rename, and change the extension from .dat to what you think it should be — .avi, .mov, .mp4, or whatever matches the file type.

Be cautious with this approach. If you rename a file and it does not work, you can always rename it back. But renaming should be a last resort, not a first attempt, because you might guess wrong and corrupt the file in the process. This method works best when you have other context — for example, if you found a DAT file in a folder full of video files, or if someone told you "I saved a video as DAT by accident." Without that context, renaming is just guessing.

Accept that some DAT files cannot be opened outside their program

Many DAT files are proprietary — they are designed to be read only by the program that created them, and no other program can open them. This is common with game files, specialized software, and some backup programs. If you have tried the steps above and nothing works, the file probably falls into this category.

If you need to use the data inside, your only option is to install or use the program that created it. If you no longer have that program or cannot find it, the file may be unreadable. This is one reason to keep installation files or to note what programs you use to create important files — it makes recovery much easier later.

Frequently Asked Questions

Is it safe to open a DAT file I found online?

Opening a DAT file in a text editor or media player is safe — these programs can only read files, not execute them. However, if someone tells you to run a DAT file as a program or double-click it without knowing what it is, be cautious. Malware can hide in any file type. Only open DAT files from sources you trust.

Can I convert a DAT file to another format?

Only if you can open it first. Once you know what program reads it, check that program's menu for an Export or Save As option. Some programs let you save to other formats; others do not. If the program has no export option, the file may be locked to that format.

What if the DAT file is from an old program that no longer exists?

Search online for the program name plus "DAT file" or "file format" — someone may have documented what the format contains. If the file is video or audio, try VLC. If it is settings or data, you may need to find an archived version of the original program, which is sometimes available through archive sites or the program's developer.

Should I delete DAT files I find in my program folders?

No, unless you are certain what they are. DAT files in program installation or settings directories are usually cache, logs, or configuration data that the program needs to run. Deleting them can cause the program to malfunction or lose settings. Only delete them if you have looked up what they are and confirmed they are safe to remove.

Why do some programs save files as DAT instead of a real extension?

Sometimes it is intentional — the program wants to prevent users from opening the file in other programs or accidentally editing it. Sometimes it is a bug or a default behavior that the programmer never changed. And sometimes the program is old and was written before standard file extensions became common.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.