Healthcare.gov, the error-riddled website where uninsured Americans are supposed to shop for health insurance, now works for "in the zone of 80 percent" of users, a White House official said today. That's up from just 30 percent of users who were able to navigate through the entire site five weeks ago.

Officials say the site can now support its original goal of 50,000 users, even though it failed to support even 200 to 300 concurrent users in tests a few days before launch.

"While we still have work to do, we have made significant progress with Healthcare.gov working for the vast majority of users," Jeff Zients, who is leading the effort to repair Healthcare.gov, told reporters on a press call today.

The improvement is the result of more than 400 software fixes and hardware upgrades, including a significant hardware upgrade on Friday night that roughly doubled the site's capacity.

The error rate, which the government defines as system timeouts or failures, is now around 0.75 percent, down from more than 6 percent. Response times have been under a second for the last three weeks, down from eight seconds.

It's all good news for users who have been trying to buy insurance through the site but were stopped by bugs and long wait times. But new data released by the White House also shows just how underprepared Healthcare.gov was when it launched.

For example, while uptime is now around 95 percent, it was only 42.9 percent at the beginning of November.

Documents released by the White House also show that hardware capacity was initially about a quarter of what was needed for the registration database, around a third of what was needed to support the core database, about half of what was needed to support the website, and only one fifth of what was eventually needed to support the firewall.

After an assessment in mid-October, the administration set a goal of fixing the website for the "vast majority" of users by November 30th. That metric was later refined to 80 percent of users. With today's announcement, the White House can say it has met that goal — although critics will point out that that means 20 percent of users are still having trouble.

"The status of HealthCare.gov in October was marked by an unacceptable user experience," says a report released by the Department of Health and Human Services, which oversaw the effort to build and then bolster the site. "Dramatic progress has been made on improving Healthcare.gov. While we strive to innovate and improve our outreach and systems for reaching consumers, we believe we have met the goal of having a system that will work smoothly for the vast majority of users."

The team will continue to work to improve the site, Zients says, with contractor QSSI leading the effort with "private sector speed and focus."

The team also implemented a queuing system in case the system gets overwhelmed with demand as the Affordable Care Act (ACA) deadline for purchasing health insurance approaches. If the site is at capacity, users will be asked for their email address. The system will email them a time to return to the site and a link to jump to the front of the queue.

The White House will now attempt to gradually guide people back to the site in order to sign up uninsured Americans by December 23rd, the deadline for having coverage by January 1st. Under the new law, Americans may be fined for not having health insurance.