A Grammy-nominated engineer (Michael Jackson, Kelly Clarkson, Carrie Underwood) masters your songs with a 48-hour turnaround time.

Engineer Ron Boustead has 20 years of mastering experience and has worked with Frank Sinatra, the Rolling Stones, The Eagles, and others. Resolution is based in Van Nuys, California.

Billing itself as the world's first online mastering studio (established in 2003), chief mastering engineer Lorenz Vauck is a German engineer who masters for artists all over the world.

Established in 2004, clients include A Ha, Orbital, Judas Priest, and John Williams (guitarist). eMasters was the first high-end studio in the United Kingdom to offer an online mastering service.

Online mastering done at Metropolis studio in London, which they claim was named one of the world's top 3 mastering studios. Choose from one of nine engineers who have worked with The Beatles, The Who, David Bowie, and others.

Get your music mastered in legendary recording studio Abbey Road Studios where The Beatles, Pink Floyd, Radiohead, U2, and others have recorded. Log into their web system to upload your tracks.

Geared specifically to independent artists, 48hourmasters.com offers competitive rates for professional mastering by lowering their overhead costs and providing the service online.

Norway-based online mastering serving customers all over the world, with a convenient currency calculator for converting rates. Their engineer has 15 years of experience.

Offering several choices between engineers (with varying levels of experience and different rates), Mastering World provides artists several options for online mastering while many other sites typically stick to one or two engineers.