The Center for New Testament Restoration (CNTR) transcoding tool converts text between different Greek character formats and encodings.

Greek Characters

Greek characters can be represented in Unicode, Beta Code, or the Symbol+ format.

Unicode – computer-encoded characters used by most operating systems maintained by the ISO/IEC 10646 standard (see http://www.unicode.org).
Beta Code – ASCII characters used to represent Greek characters with diacritical marks developed by David W. Packard and adopted by Thesaurus Linguae Graecae (see http://www.tlg.uci.edu/encoding).
Symbol+ – ASCII characters used to represent Greek characters using the Microsoft Symbol font with extensions added by the CNTR (see https://www.microsoft.com/typography/fonts/font.aspx?FMID=1650).

Unicode characters can then be represented with various encodings: UTF-8, UTF-16BE, UTF-16LE, UTF-32BE, UTF-32LE. When downloading Unicode files, the Byte Order Mark (BOM) should be included for most operating systems, but can be toggled off if needed with the ⌷ button (or Alt-b). When downloading ASCII files (for Beta Code or Symbol+), the UTF-8 format should be selected and the BOM should be toggled off.

The initial character format is automatically detected based on the first several characters whenever a file is uploaded or by clicking in the Convert dropdown menu. After the initial character format is set, the program can convert between any of the character formats from the convert dropdown box. A warning is given if the characters are being converted to the Symbol+ format, because all normalized diacritical marks would be lost.

Transformation

Unicode characters can be normalized (joined with diacritical marks) or decomposed (separated from diacritical marks) by pressing the appropriate button (N or D). Normalization can also replace characters with more standardized forms and this process is not reversible. For example, a Greek vowel using a single oxia accent to represent the acute accent, would be normalized to the tonos accent. Normalization and decomposition do not have any effect on the Beta Code or Symbol+ characters.

Typing

The default operating system keyboard is used when typing, but this can be toggled to use GreekKeys with the ⌨︎ button (or Alt-k). The GreekKeys characters are generated by typing Beta Code characters on the keyboard. Individual Greek Unicode characters can be selected by clicking on the αβγ button. The characters shown in brown are unnormalized characters that would be changed if normalized. Text wrapping can be toggled with the ↩ button (or Alt-w).