UUEncode/UUDecode - Unix-to-Unix Encoding Tool

Encode and decode files with UUencoding. Classic Unix binary-to-text encoding for email and Usenet. Includes XXencode variant support.

Input

Drop file here or click to browse

Filename (for encoding)

Output

Format Info

Encode or decode to see format details

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Frequently Asked Questions

UUencode (Unix-to-Unix encoding) converts binary data to ASCII text for transmission over text-only channels. Developed in 1980 for UUCP email and Usenet.

It takes 3 bytes of binary data and converts them to 4 printable ASCII characters (space through backtick). Each line starts with a length character.

UUencoded files start with 'begin [mode] [filename]' and end with 'end'. The mode is Unix file permissions (e.g., 644). This header preserves file metadata.

Rarely. Base64 (MIME) replaced UUencode for email attachments. You may encounter it in legacy systems, old Usenet archives, or Unix shell scripts.

Both encode binary to text, but Base64 uses A-Z, a-z, 0-9, +, /. UUencode uses space through backtick (ASCII 32-95). Base64 is more widely supported.

XXencode is a variant using +, -, and 0-9, A-Z, a-z instead of space-backtick. It avoids whitespace issues that sometimes corrupted UUencoded data.

UUencode expands data by about 37% (3 bytes become 4 characters, plus line length chars and headers). Similar to Base64's 33% overhead.

Yes. UUencode works on any binary data - images, executables, archives, etc. It was the standard way to share binary files on text-only Usenet.

Modern email clients handle this automatically. For manual decoding, use this tool or Unix 'uudecode' command. Look for 'begin' line to find encoded content.

Large files were split across multiple Usenet posts. You'd need to combine parts in order before decoding. Each part has the same begin header.

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