A tweet from GoDaddy said, "Status Alert: Hey, all. We're aware of the trouble people are having with our site. We're working on it," and a voice message on the company's customer service line also acknowledged the outage, CBS news reported.
"If you are having a problem with your e-mail, we are aware of the problem," the message said.
Tweets from Twitter accounts claiming to be associated with the hacking group Anonymous took responsibility for the attack.
"By using/supporting Godaddy, you are supporting censorship of the Internet," a tweet from @AnonOpsLegion said.
GoDaddy has been the target of protests for supporting the controversial Stop Online Piracy Actand Protect IP Act.