The browserfor free download at 1 a.m. PST Tuesday. But by early Tuesday morning, only 45 percent of those who tried to gain access to the Web site were successful, said Stephen Pierzchala, senior analyst at Net performance management firm Gomez. And for those who were lucky enough to gain access, it took an average of 40 seconds to 50 seconds to load the page via a T1 line or better. For popular sites such as Amazon.com and Yahoo, it takes about 4 seconds to load the entire page, he said.
"Firefox is suffering from a success crisis," Pierzchala said. "The bad news is so many people can't get to the site. The good news is its popularity."
The Mozilla Foundation said it had been bracing for a wave of users and took additional precautions prior to the launch.
"One thing in the last several weeks we've done to prepare for the arrival of Firefox 1.0 is to beef up our server capacity," Chris Hofmann, engineering director at the Mozilla Foundation, wrote in an e-mail. "The traffic we received for the preview release was greater than anything the foundation had experienced. We did some planning and estimation around this prior to the 1.0 launch, and today the traffic is far exceeding our expectations."
"We have some additional servers and bandwidth in reserve actually, and we're adding that as quickly as we can," he added. "We are starting to see performance improvement in the site at this hour, and we expect that to continue."
Pierzchala said that by midday, that 40-second delay was down to about 7 seconds, on average, via a T1 line or better. He added that the Mozilla site had shown signs of sluggishness even a couple of hours before the browser's release.
"Performance was already slowing at 11 p.m. last night," he said. "People were probably looking to see if it had been released yet and kept hitting refresh."
The Mozilla Foundation offers a list of mirror sites, which are alternative Web sites that host the file and serve as another means to get the data. However, accessing the Mozilla site to retrieve that information has been problematic.
"What you'll probably see are blogs or chat forums where they will post information on mirror sites, so you don't have to go to the Mozilla site," Pierzchala said. "Often you'll see the community help each other out and point to locations where the file is available and take pressure off of the primary site."
A representative for the Mozilla Foundation said the group will not be able to be determine the number of downloads of Firefox 1.0 until Tuesday night.
CNET News.com's Paul Festa contributed to this report.