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Text Codecs (SeaMonkey, Mozilla, Thunderbird, Firefox)

Text Codecs Context Menu
Text Codecs Context Menu

What are Text Codecs?

The term "codec" is actually just a short way of referencing encoders and decoders with a single word. Thus, a Text Codec is a function that transforms text into (when encoding) or out of (when decoding) another kind of representation. Usually, the most human-readable representation is said to be "decoded".

Mnenhy provides two new context menu items, "Encoders" and "Decoders", for the browser window, the mail display, the mail editor and various source view windows, containing a large number of useful text codecs. "Encoders" will turn the (selected or whole) text into something less readable, "Decoders" try to revert those effects as good as possible.

Available Text Codecs


ROT-13 is an application of the classic "encryption" method, the "Cesar cipher": every letter of the alphabet is exchanged with that in 13 places distance.

ROT-13 is symmetric, i.e. encoder and decoder are the same function.

Decoded TextEncoded Text


Base64 is used to represent non-ASCII characters or binary data by just 64 printable ASCII letters.

Decoded TextEncoded Text


The UU encoding scheme is quite similar to Base64 in its usage to represent non-ASCII characters or binary data just by printable ASCII letters.

Decoded TextEncoded Text

URI Codecs

URI encoders replace characters by the hexadecimal representation of their ISO-8859-1 byte value, prepended by a % sign. The various functions of this group encode a different set of characters.

Decoded TextEncoded Text

Unicode Codecs

Unicode encoders replace characters by a representation of their UTF-8 byte value, with spaces as delimiters. The various functions of this group encode with regard to a different representation base.

Decoded TextEncoded Text
Mnenhy01001101 01101110 01100101 01101110 01101000 01111001


Kenny is a fun codec, based upon an idea by Kohan Ikin. It's said to mimic the way of speaking of Kenny McCormick.

Decoded TextEncoded Text


Morse is the official radio alphabet, build upon just two states: a long pause - and a short pause . between signals.

Morse is not fully revertable, because certain text characteristics like "case" do not exist.

Selected Text Encoded Text Decoded Text
(Mnenhy) -- -. . -. .... -.-- (mnenhy(


1337 is another fun codec, rooted in the hacker subscene ("1337" = "leet" means "elite").

This codec is not always right in guessing, since there're way too many dialects of 1337 speak.

Decoded TextEncoded Text


Reverse does just that: the last character becomes the first, the second-to-last becomes second, and so on...

Decoded TextEncoded Text

Case Encoders

Case encoders transform all characters into the target case.

These encoders are lossy and hence not revertable. The table below shows the result of the "Upper Case" encoder.

Selected TextEncoded Text


This special codec allows for user defined text alteration. The currently selected text is stored in a variable named asContent, the user can enter a JavaScript expression which will be evaluated and the result replaces the selected text.

The table below shows the result of the user input

var s=""; for (var i=0; i<asContent.length; ++i) if(asContent[i]>"m") s+=asContent[i]; s;
Selected TextResult

Tips & Tricks

The Unicode decoders can be used to enter characters that are either not accessible via the keyboard (like ⇔) or are killed by the Mozilla mail editor (like the form feed character 0x0C): Just enter the Unicode of the character and decode that (hexa)decimal number with the (hexa)decimal Unicode decoder!

Decimal UnicodeDecoded Text