.CT3 File

The ct3 file extension is mainly related to an audio output format recorded using the Casio WK-1800 Keyboard.

It was a type of 76-key portable keyboard with Floppy Disk Drive for song play and storage released around 2003.

This type of ct3 files contains single user tone.

Note: This file extension is unrelated to CT-3 (General Business Corporation Franchise Tax Return) form used In NY. You have to download these forms from New York State Department of Taxation and Finance website. In this context CT is abbreviation for Corporate Tax.

How to open:

These files can probably only be played using Casio WK-1800.

How to convert:

Possibly could be converted to some other audio format, provided you will find a converter that supports it.