What Is a DIZ File?

Discover what's inside a ZIP archive with a DIZ file

A file with the DIZ file extension is a Description In Zip file. They're text files found within ZIP files that contain a description of the contents of the ZIP file. Most are called FILE_ID.DIZ (for file identification). 

DIZ files were originally used with bulletin board systems to describe to the website administrators what files the users were uploading. This process would happen automatically by having web scripts extract the contents, read the files, and then import the DIZ file into the archive.

Nowadays, DIZ files are most often seen on file sharing websites that have downloads for archives full of data. The DIZ file is present for the same purpose, though: for the creator to tell the user what it is that's contained in the ZIP file they've just downloaded.

DIZ files in Windows 10 that open with Notepad++

NFO (information) files serve a similar purpose as DIZ files but are much more common. You may even see the two formats together in the same archive. However, according to the FILE_ID.DIZ specification, the DIZ file should contain just basic information regarding the archive's contents (just 10 lines and a maximum of 45 characters per line), while NFO files may have more information.

How to Open a DIZ File

Because DIZ files are text-only files, any text editor, like Notepad in Windows, will successfully open them for reading.

To convert from DIZ to PDF, you can use a text editor in combination with a PDF printer.

Since just opening a DIZ file won't launch it in a text editor by default, you can either try opening it and then choose Windows Notepad or, if you have a different text editor installed, open that program first and then use its Open menu to browse for the DIZ file.

If neither of the above programs work, we recommend trying NFOPad or Compact NFO Viewer, both of which support ASCII art, which some DIZ files may contain. macOS users can open DIZ files with TextEdit and TextWrangler.

If you find that an application on your PC does try to open the DIZ file you have but it's not the one you'd like, see How to Change File Associations in Windows for a quick how-to on changing the program that opens DIZ files.

How to Convert a DIZ File

Since a DIZ file is just a text-based file, you can use any text editor to save the open DIZ file to another format like TXT, HTML, etc.

You can't usually change a file extension to one that your computer recognizes and expect the newly renamed file to be usable. An actual file format conversion is often necessary. However, since a DIZ file is just a text file, you could rename FILE_ID.DIZ to FILE_ID.TXT and it would open just fine.

DIZ files are just descriptive text files, meaning they can only be converted to other text-based formats. So even though the DIZ file is found within a ZIP file, you can't convert one to another archive format like 7Z or RAR

Still Can't Open the File?

If your file won't open with the above suggestions, it's possible that you're not really dealing with a file that ends in that file extension. This might happen if you've misread the file extension, which is really easy to do.

DZ, for example, looks an awful lot like DIZ even though it could be used for something entirely different. Some DZ files are used by the video game Land of the Dead and have nothing to do with text files.

Some other file extensions that are easy to confuse for DIZ include DIF, DIC, DIB, and DIR.