You can open .DAT files that contain text, with text editors, like Notepad, Notepad++, VS Code, etc. But it is not possible to know what contains in a DAT file.

Though DAT files, which house data as the shortened name implies, are usually best left alone, here's how you can open them.

If you're having trouble opening a DAT file, I'll show you a simple and free way to do it. This method works on both Mac and PC. Just open your browser and go to winmaildat.com. It's a ...

Tips on opening a winmail.dat file, keeping seldom-used ink cartridges from drying out, and undoing an Undo.