In the 24 hours from early Wednesday to early Thursday, users downloaded 8.75 million copies of the new browser, an uptick from the 7.1 million logged by Firefox 4 its first day.
Last week’s one-day tally broke the record established by Firefox 3.0 in mid-2008 when that browser was downloaded more than 8 million times within 24 hours. Then, Mozilla ran a “Download Day” campaign that resulted in a certified Guinness World Record .
Mozilla launched the final version of Firefox 4 around 6:30 a.m. PT Tuesday after more than a year of development.
Although Firefox 4’s downloads bested Firefox 3’s record, the achievement won’t be official. In 2008, a Guinness representative monitored Mozilla’s download servers to audit the number; no on-site official was present at Mozilla last week, a company spokeswoman said.
Firefox also thrashed Microsoft’s Internet Explorer 9 (IE9) on the download count. Last week’s 8.75 million for Firefox 4 was almost four times the 2.4 million Microsoft touted the week before as the 24-hour count for IE9 when it launched March 14 .
That didn’t surprise one analyst, who cited pent-up demand for Firefox because of several months’ worth of delays, and the difference between Firefox and IE9 users.
“The Firefox user base is primarily power user, with a much smaller percentage of corporate users compared with IE9,” said Al Hilwa, an analyst with IDC. “Most large IE9 corporate users [work in] lock-downed environments, and so upgrading is under IT control and, thus, slower.”
The advantage also goes to Firefox 4 because it runs on Windows XP, the 10-year-old operating system that IE9 has left behind. “Supporting XP will ultimately lead to improving share for Firefox 4 as HTML5 proliferates and users with XP machines want to participate in that,” Hilwa said.
According to Web metrics company Net Applications, XP currently accounts for more than 61% of all copies of Windows in use.
Unlike IE9, Firefox 4 also runs on Mac OS X and Linux.
Because of those advantages, Hilwa has high hopes for Firefox. “All indications are that Firefox 4 will end up being a blockbuster release for [Mozilla], helping them gain their mojo back at least for some time to come.”
By Sunday, Mozilla’s real-time scoreboard claimed that over 35 million copies of Firefox 4 had been downloaded since Tuesday.