Yintong is an online database of characters in the Guǎngyùn 廣韻, a dictionary dating from 1008 C.E., created by David Prager Branner.
The database has the following main functions:
- Lookup by character, returning information about the fǎnqiè associated with the character, the phonological values represented by those fǎnqiè, and the page number of the Guǎngyùn where that reading appears.
- Lookup by medieval Chinese reading, returning a list of the other characters in the same xiǎoyùn.
- Lookup by two medieval Chinese readings, returning a list of any characters appearing in both xiǎoyùn.
- Lookup by multiple characters, returning a transcription of each character based on the Guǎngyùn’s readings.
Further details: http://yintong.americanorientalsociety.org/html/about.htm.