The mini Compact Disc single (mini CD single) was an optical disc format for music singles based on the Compact Disc. Mini CD singles are 3-inches in diameter, compared to full-size CD singles which are the same size as standard CDs, 5-inches. Because of this, mini CD singles are sometimes known as CD3s.
They can be played in most devices that can play standard CDs, with the exception of slot-loading drives. Some CD players require an adapter to play mini CD singles. Mini CD singles meet the Red Book standard for Compact Discs, but store less data (about 21-24 minutes maximum).
The format was first released in the UK in 1988, and most mini CD singles contained at least two tracks, in the same way as 7-inch vinyl singles.
Sony released a model in the Discman series that was designed around the mini CD, the Discman D-88, which could also play full-size Compact Discs despite them being larger than the device.
The format lasted into the early 1990s in the UK, when most CD singles were released on full-size CDs as they were cheaper to manufacture due to their standard size. Since then, some mini CD singles have been released for novelty value.
