The entire ObamaCare Web site was suddenly taken down for 11 hours — from Friday night into Saturday morning — just before its long-awaited ­relaunch.

Officials said the extended shutdown, which began 9 p.m. Friday, was required to get the site ready to accept double the number of applicants starting Saturday.

“We have more upgrades that require more time,” said Aaron Albright, a spokesman for the Centers for Medicare and Medicaid Services, which oversees the problem-plagued portal.

The site has been taken down before, but usually only for four hours between 1 and 5 a.m.

Even before the unexpected move, health-industry experts were skeptical that the fix that’s supposed to produce a “new and improved” site Saturday would be the game-changer President Obama has promised.

One insurance broker in Arizona — who has signed up just two clients through the site since it opened Oct. 1 — warned that no amount of repair could win back applicants.

Broker Jerry Anderson said people in his state have had such awful experiences on Healthcare.gov that they’re going to stick with the insurance they have as long as they can.

“They’re going to wait a year for the dust to settle,” he predicted.

Anderson also said that those who have no choice but to enroll in ObamaCare are nervous.

“We’re running out of time to enroll people for January 1. It’s hard on everybody. There’s a lot of angst out there,” he said.

Obama has pledged that the “vast majority” of Americans would be able to sign up for the new national health plan once the site is fixed.

The trade association representing the nation’s health insurers responded with a “we’ll-believe-it-when-we-see-it” position.

“Healthcare.gov and the overall enrollment process continues to improve but there are significant issues that still need to be addressed. Until the enrollment process is working from end to end, many consumers will not be able to enroll in coverage [by Jan. 1],” cautioned Karen Ignagni, CEO of America’s Health Insurance Plans.

Administration officials said an increase in the site’s capacity should double the number of consumers who can simultaneously sign on, to 50,000 an hour.

Health and Human Services Secretary Kathleen Sebelius on Friday even published a “Holiday Shopping Tips guide for signing up without the hassles that have made the site a national laughingstock.

“There are 23 shopping days in December [until the deadline for coverage that starts Jan. 1]. No need to rush,” Sebelius advised in an attempt to avoid a panicked rush of the uninsured on Saturday.