UUencode / UUdecode

UUencoding is one of the oldest binary-to-text encodings in the Unix world, developed in the early 1980s to transfer binary files over UUCP (Unix-to-Unix Copy) networks that could only handle ASCII text. You will encounter it in old Usenet archives, legacy shell scripts, and source code that predates MIME. Understanding UUencode is essential for working with historical Unix data.

This tool encodes text or binary data to UUencode format — complete with the `begin` and `end` markers and permission mode that define a valid UU file — and decodes UUencoded blocks back to their original content. Useful for preserving or migrating legacy archive content, analysing old mail archives, and understanding how binary transfer worked before Base64 became universal.

UUencode und UUdecode online

1. 1

   Eingabe einfügen

   Fügen Sie Text oder Binäreingabe zum Kodieren als UUencodierten Block ein, oder fügen Sie einen vorhandenen UUencodierten Block (einschließlich begin- und end-Zeilen) zum Dekodieren ein.

2. 2

   Kodieren oder Dekodieren

   Das Tool erzeugt oder parst die begin/end-Markersyntax und validiert die Blockstruktur.

3. 3

   Ergebnis kopieren

   Kopieren Sie den kodierten Block oder den dekodierten Inhalt. Nützlich für Legacy-E-Mail-Archive, Usenet-Daten und CTF-Challenges.

How UUencoding Works

UUencoding converts three input bytes (24 bits) into four output characters, similar to Base64, but uses a different 64-character alphabet. Each 6-bit group is mapped to an ASCII character by adding 32 to its value, putting output characters in the range 32–95 (space through underscore). Each output line is preceded by a length character — the number of bytes encoded on that line plus 32 — allowing the decoder to determine exactly how many bytes each line represents.

A UUencoded file begins with `begin MODE FILENAME` where MODE is the Unix file permission octet and FILENAME is the original filename, and ends with a line containing a grave accent (`` ` ``) followed by `end`. The filename and permissions are part of the encoding, which makes UUencode slightly richer in metadata than Base64, though this advantage is rarely useful today.

Warum FileCrank UUencode / UUdecode verwenden?

• ✓ Erzeugt und parst korrekte begin/end-Markersyntax.
• ✓ Validiert Blockstruktur und meldet Fehler klar.
• ✓ Verarbeitet Legacy-E-Mail- und Usenet-UUencodierte Anhänge.
• ✓ Läuft vollständig in Ihrem Browser — keine Daten werden an einen Server gesendet.

Funktionen & Spezifikationen

Max. Dateigröße

Bis zu 100 MB

Datenschutz

DSGVO-konform: Dateien werden nach etwa einer Stunde gelöscht

Preis

Kostenlos, keine Registrierung

Verarbeitung

100% clientseitig

Häufig gestellte Fragen

UUencode vs. Base64 vs. MIME

UUencode is historically significant but obsolete for new work. Base64 is strictly superior: it is more widely implemented, has a cleaner alphabet that avoids the space character (which caused corruption in some mail systems), and is defined in MIME standards that every modern email client and HTTP library understands. Use this tool to read legacy data rather than to produce new encodings — for any new binary-to-text need, Base64 is the right choice.

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