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UU File

What are UU files and how to open them

Are you having problems opening an UU file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your UU files.

What is an UU file?

UU files have multiple uses, and UUEncoded is one of them. Read more about the other uses further down the page.

UUEncoded file

Files using the .uu file extension are uuencoded Unix files. The word "uuencoded" is derived from the Unix-to-Unix encoding process.

The Uuencode program takes the application's binary files and converts them into a text-based file format. These files are commonly used to email documents and prevent the documents from being corrupted during file transfer. The UCCP process converts characters between computer character sets.

These files are often destroyed when a user tries to open the file if the file has not been unencoded. Hence, the UUENCODED file format. Once a file has been sent using the UU file format, the file must be unencoded before the recipient can open the original file on his or her hard drive.

How to open UU files

We have identified four UU openers that are compatible with this specific type of UU file.

Programs that open UUEncoded files

Stuffit ExpanderStuffit ExpanderVerified

Last updated: February 24, 2023

All known file formats using extension .UU

While UUEncoded file is a popular type of UU-file, we know of 2 different uses of the .UU file extension. Different software may use files with the same extension for different types of data.

UUencoded Base64 Text

We know that one UU format is UUencoded Base64 Text. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about UU file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.