Text view
Read settings, logs, license keys and other plain-text DAT files. Search for any word and export the text as a .txt file.
Reading text DAT filesFree online DAT file opener
DAT File Viewer — Open & Read DAT Files Online Free
Open any .dat file right in your browser. See readable text, turn comma- or tab-separated data into a table, or check the raw bytes in hex. Nothing to install, no sign-up.
- 100% free
- No upload, your file stays on your device
- Text, Table & Hex views
- Windows, Mac, Android & iPhone
DAT
File preview will appear here.
- Any file size can be opened
- Previews up to 5 MB of text
- 5,000 table rows
- 1 MB in Hex view
- Export to TXT or CSV
Step-by-step
How to open a DAT file
A .dat file is a generic data file. Games, email programs, attendance machines, drones and
business software all save files with this extension, and each one stores something different inside.
That is why double-clicking a DAT file often does nothing, or opens a screen full of symbols.
Quick answer: to open a DAT file, drop it into the free viewer above and see what is inside. If you see readable words, it is a text file you can also open in Notepad or TextEdit. If you see rows separated by commas or tabs, use Table view or import it into Excel. If you see only symbols, it is a binary file that needs the program that created it.
- Check where it came from An email attachment, a game folder, a time clock or a drone? The source is the best clue to the right program.
- Open it in the viewer Click the upload box above, or drag the file in. It opens instantly and nothing is uploaded.
- Pick the view that fits Text for readable content, Table for records, Hex for binary data. Search inside the file in any view.
- Save or use the right app Export text or CSV, or, for proprietary files, open them in the software that created them.
Need steps for a specific device? See how to open a DAT file on Windows 11, Windows 10, Mac, Android, iPhone or Linux.
DAT file reader
Three ways to read a DAT file
The viewer checks your file and opens it in the view that fits best. You can switch views at any time.
Table view
Rows separated by commas, tabs, semicolons or pipes are shown as a clean table, ready to export as CSV for Excel or Google Sheets.
Opening DAT data in ExcelHex view
For binary DAT files, the hex viewer shows the raw bytes. The first bytes often reveal the real
format. 1F 8B, for example, means the file is gzip-compressed.
Know your file
Common DAT files and how to open them
Find your file below to see what it usually contains and the best way to open it.
| DAT file | What it usually is | How to open it |
|---|---|---|
| winmail.dat | An Outlook email wrapper that hides the real attachments. | Use a winmail.dat (TNEF) extractor, or ask the sender to resend in HTML or plain-text format.
Hex view only here |
| Attendance logs (ZKTeco, e.g. attlog.dat) | Clock-in records exported from a fingerprint or time-clock machine. | Usually tab-separated text. Use Table view, then Export CSV for Excel.
Opens here |
| Data logger & lab files | Sensor or measurement data, e.g. from LabJack or other loggers. | Often tab- or comma-separated. Use Table view and export to CSV.
Opens here |
| License & config files (lic.dat, settings.dat) | Program settings or license keys. | Usually plain text. Use Text view or Notepad. Don't edit without a backup.
Opens here |
| Minecraft (player.dat, level.dat) | Compressed game save data (NBT format). | Hex view confirms it (starts with 1F 8B). Use an NBT editor to change it.
Hex view only here |
| Game resource files (e.g. audiogroup.dat) | Packed game assets such as sounds or graphics. | Needs a tool made for that game engine. Hex view shows the header.
Hex view only here |
| Drone flight logs (.DAT) | Flight records saved by the drone, usually encoded. | Use the drone maker's app or a flight-log converter.
Hex view only here |
| Video CD (AVSEQ01.DAT) | MPEG video from an old Video CD. | Play it in VLC media player. This viewer does not play video.
Hex view only here |
| wallet.dat | A cryptocurrency wallet (e.g. Bitcoin Core) with private keys. | Open only in the wallet software. Never upload it to any online service or share it.
Use the wallet app |
Not in the list? Open it in the viewer above and look at the Text or Hex view for names, paths or version strings, then see how to find the program that created a DAT file.
The basics
What is a DAT file?
DAT simply stands for "data". Unlike JPG, PDF or MP3, a .dat file has no single
standard layout. Every program decides for itself what goes inside, so one DAT file might be plain
text, another a table of records, and another a compressed or encrypted binary file.
That's why the safest way to open a DAT file is to look inside first, and why
renaming file.dat to file.jpg or file.csv doesn't convert it.
Read the full guide to DAT files.
Any device
A DAT file opener for every device
The viewer runs in your web browser, so you don't need a separate DAT file viewer for Windows, a Mac app or an Android download. Open this page, choose the file and read it.
Large files
Can it open big DAT files?
Yes, you can select a DAT file of any size, even hundreds of MB or several GB. To keep your browser fast, the viewer previews the beginning of the file: up to 5 MB of text, 5,000 table rows and 1 MB of hex. That's almost always enough to see what the file is. For full processing of huge datasets, a desktop tool built for large files is the better choice.
Private & safe
Your file never leaves your device
The DAT file is read by your own browser. It is not uploaded to our server, so it's safe for work files and personal data. Viewing a file's text or bytes cannot run any code. As with any file, keep an untouched copy before you edit or convert it. Privacy policy.
DAT file guides
Find the right guide for your file
Not sure what your DAT file is, or want to open it in another program? Start here.
Understand your DAT file
Open DAT files on your device
Questions
DAT File Viewer FAQ
How do I open a DAT file?
Drop the file into the free DAT file viewer at the top of this page. If Text view shows readable words, you can also open it in Notepad or TextEdit. If you see rows separated by commas or tabs, use Table view or import it into Excel. If you only see symbols, the file is binary and usually needs the program that created it.
Is this DAT file viewer free?
Yes. The DAT file opener is completely free, with no account, sign-up or download.
Is my DAT file uploaded to your server?
No. The viewer reads the file with your own browser, so the file is not sent to our server.
Can it open every type of DAT file?
It can open any DAT file for inspection, but it can only fully read text and table-style files. DAT is a general extension, not one format. Proprietary files from games, databases or other software can be checked in Hex view, but they need their original program to be used properly.
Why does my DAT file show random symbols?
The file is probably binary, compressed or encrypted rather than text. Switch to Hex view and look at the first bytes and any readable words. They often reveal which program made the file. Symbols alone do not mean the file is damaged.
Can I convert a DAT file to CSV or Excel?
Yes, if the file holds records separated by commas, tabs, semicolons or pipes. Open it, switch to Table view and click Export CSV, then open the CSV in Excel or Google Sheets. Binary DAT files cannot be converted just by renaming them.
Can I open a large DAT file (hundreds of MB or several GB)?
Yes. Any size file can be selected, and the viewer previews the beginning of it: up to 5 MB of text, 5,000 table rows and 1 MB in Hex view. That is usually enough to identify the format. For full analysis of very large files, use a desktop tool built for large files.
How do I open a winmail.dat file?
Winmail.dat is an Outlook email wrapper that hides the real attachments. This viewer can show its raw bytes, but to get the attachments out you need a winmail.dat (TNEF) extractor, or ask the sender to resend the email in HTML or plain-text format instead of Rich Text.
Does the DAT viewer work on Android and iPhone?
Yes. Open this page in Chrome, Safari or another modern browser, tap the upload area and pick the DAT file from your Files app or Downloads folder.
Open your DAT file now
Drop it into the free DAT file viewer and see what's inside in seconds. No upload, no install.
Open DAT File