SAN JOSE, Calif. — Napster's song-sharing service was offline Monday as it worked to transform itself into a music company for paying customers.
Napster did not say when its computer servers would come back online, and it was not clear exactly how the down time related to Napster's planned launch of a subscription service, promised for later this summer.
The company has also been upgrading its music-identification system to better comply with court orders that it prevent unauthorized music-swapping.
Napster representatives did not immediately return calls for comment.
The Redwood City-based company was sued by major record companies for copyright infringement for allowing computer users to swap songs for free. As a result, it is transforming itself into a fee-based system that will pay royalties to the artists.
Napster is testing "fingerprinting technology" for the company's planned commercial service, said Matt Bailey, an analyst with Webnoize, an Internet research firm.
The company has begun playing hardball lately with its users, who have long traded MP3 file versions of popular music with little regard to copyright issues. The latest version of the Napster application, a forced upgrade to the system that no longer allows the use of previous versions, contains new filtering technology to identify song files accurately.
The result has been a drastic drop in the number of songs shared and the number of users sharing them.
On June 27, a snapshot of Napster activity revealed 320,000 users sharing an average of 1.5 songs each, a dramatic drop from an average 1.57 million users sharing 220 songs each at the peak of the service in February, according to Webnoize.
"By further reducing the music available through the current service, Napster has provided another nail in the coffin of the service consumers originally loved," he said.
The new fee-based Napster has no specific launch date, but has been promised before summer's end by German media giant Bertlesmann AG, Napster's primary financial backer.