Roughly 4.7 million Americans went online Tuesday to browse the Obamacare health insurance exchanges prompting HealthCare.gov administrators to increase the site's server capacity and create a new "wait page" to hold a person's place in line until the site can load properly.
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On top of the Web traffic, 190,000 Americans used federal health insurance exchange call centers and another 104,000 requested live chats.
"Now that quality, affordable coverage is within reach, we're seeing that pent up demand break through, underscoring once again how important it was to fix our broken health care system," Centers for Medicare and Medicaid Services spokesman Richard Olague told ABCNews.com.
State-run insurance exchanges reported similar Web and call center volume, causing sluggish sites and long phone wait times. But overall, the launch of Obamacare was viewed by many as "successful."
"The amount of interest we've seen and the way that the system is functioning overall, we're very happy," said Ben Davis, a spokesman for Colorado's marketplace Connect for Health Colorado, which drew 79,000 online visitors Tuesday.
Davis said Colorado "navigators" – helpers charged with steering shoppers through the purchasing process – fielded roughly 3,700 live chats and calls on the first day the exchanges were open with an average phone call wait time of 3 minutes and 49 seconds.
"Frankly, it was a pretty successful day," he said, adding that about 5,500 people created accounts to purchase a plan. "And based on what little numbers I've seen so far, traffic continues to be on pace with yesterday's in many respects."
Oregon's marketplace, Cover Oregon, drew roughly 122,000 visitors and 3,500 phone calls accounting for nearly 21 percent of uninsured people in Oregon, according to state officials.
"Our first day was a good day," Cover Oregon's executive director Howard King said in a statement. "While we experienced some bumps, as we knew we would, we had a successful first day and I'm so grateful to our staff and partners for all they've done to get us here."
"We ask that you have patience as we work hard to fix bugs and update features in what we believe is a top-notch system for Oregonians," he added.
Although the marketplaces were spared from federal furloughs, a surge in Web traffic has been blamed for frustrating lags and error messages throughout the day. Americans trying to scope out their options at HealthCare.gov are instructed to "please wait" for the login page, which in some cases took several minutes to appear.
"We have a lot of visitors on our site right now and we're working to make your experience here better," the site message reads. "Thanks for your patience!"
Health and Human Services Secretary Kathleen Sebelius warned Monday that "glitches" would be inevitable, comparing it to Apple's latest software upgrade.
The New York State of Health page had a similar message, explaining that 2 million people visited the site within the first two hours of launch, causing bottlenecks.
"We encourage users who are unable to log in to come back to the site later when these issues will be resolved," a message at the top of the site read.
A sampling of state sites found that health exchange websites in Vermont, Connecticut, Kentucky and Washington were slow to load.
"Commonwealth of Kentucky citizens have shown tremendous response to KYNECT since we established our marketplace," a message on its site read. "The KYNECT Website is currently experiencing log in issues and our technical team is working to resolve the problem."
Other state health care exchanges, including California's, seem to be working normally.