Chaku Uta is a digital transmission technology used to distribute ringtones and pop songs to the generation of Japanese mobile phones refered to as 'keitai'.
The Chaku Uta digital distribution technology is owned by Sony Music Entertainment and used under licence by most major Japanese mobile phone service providers. 'Chaku Uta' and 'Chaku Uta full' are registerd Sony trademarks.
'Chaku Uta' （着うた） refers to the distribution of 45 second ringtones. 'Chaku Uta full' （着うたフル） refers to the distribution of pop songs.
'Chaku Uta full' download services began in Japan in 2004. From August 2006 to December 2013, RIAJ monitored and tabulated Chaku Uta full downloads and published certifications for download sales in the following categories:
- Gold - 100,000 downloads
- Platinum - 250,000 downloads
- Double Platinum - 500,000 downloads
- Million- 1,000,000 downloads
- Double Million - 2,000,000 downloads.
At the height of it's populatity the Chaku Uta full format accounted for about 90% of all japanese music downloads. However the advent of Android and iPhone smartphone devices which use PC distribution technology eroded the market dominance of the Chaku Uta full format. At the end of 2013 RIAJ took the decision to cease tabulating Chaku Uta full downloads separately.
From January 2014, all paid download sales of single music tracks are being tabulated in a single category. The decision to merge the Chaku Uta full and PC categories led to the publication of a list of revised download certifications on 2014-02-28.