However, the number of available languages has been expanded by the users. UTAU is mostly a Japanese program and thus many of its voices are created specifically for the Japanese language. These voicebanks are normally distributed directly from their creators via internet download, but some are sold as part of commercial projects. A myriad number of voicebanks have been developed by independent users. They are also called 'voicebanks' (more common in English-speaking areas) and '(voice) libraries' in Japan. Voices made for the UTAU program are officially called 'UTAU' as well, though they are colloquially known as 'UTAUloids', a reference to VOCALOID.

It comes with AQUEST's voice synthesizer ' AquesTalk' for synthesizing the voice samples of the default voicebank, Utane Uta (also nicknamed Defoko ( Defoko meaning 'Default Girl' in Japanese)) on UTAU's initial launch, after which the generator deletes itself. UTAU is able to use WAV files provided by the user, so that a singing voice can be synthesized by introducing song lyrics and melody. UTAU was originally created to assist this process using concatenative synthesis. UTAU ( 歌う), meaning 'to sing' in Japanese, has its origin in the activity of 'Jinriki Bōkaroido' ( 人力ボーカロイド, Manual Vocaloid), where people edit an existing vocal track, extract phonemes, adjust pitch, and reassemble them to create a Vocaloid-esque singing voice. In March 2008, Ameya/Ayame released UTAU, a free, advanced support tool shareware software that was free-to-download from its main website.

This program is similar to the VOCALOID software, with the difference being it is shareware instead of under a third party licensing. UTAU is a Japanese singing synthesizer application created by Ameya/Ayame ( 飴屋／菖蒲). Japanese and English (and other languages via patch files)

Phonemes list for vocaloid