The College Board is halting plans to offer the SAT admissions test at home in coming months and is urging schools not to punish students who do not submit scores, further demonstrating how the coronavirus crisis has upended college admissions.

In backing away from at-home exams, the testing organization cited concerns that many students would not have access at home to the three hours of reliable Internet service that would be required to complete the multiple-choice exam.

The decision came after the College Board faced significant criticism in recent weeks from students who took its online Advanced Placement exams but were unable, because of technical glitches, to submit their answers through cellphones or computers. The online AP tests, shortened this spring to 45 minutes each, were offered after the coronavirus pandemic closed high schools across the country.

With testing schedules in tatters as a result of the pandemic, the College Board on Tuesday urged selective colleges to extend deadlines for students to submit SAT scores and hold harmless any applicants who are unable to take the test because of the virus.

In many places, demand for seats in testing sessions in August and September far outstrips the supply of centers where the SAT will be held. Social distancing restrictions and other public health measures have made large-scale administration of tests incredibly challenging.

“We know demand is very high and the registration process for students and families under this kind of pressure is extremely stressful,” David Coleman, the College Board’s chief executive, said in a statement. “There are more important things than tests right now. … We therefore are asking our member colleges to be flexible toward students who can’t submit scores, who submit them later, or who did not have a chance to test more than once.”

A growing number of prominent colleges and universities have made admission-test scores optional for the next round of admissions — but not all. Harvard and Stanford universities, among others, continue to require a score from the SAT or rival ACT.

An estimated 1 million high school juniors this spring who do not have an SAT score were blocked from taking the test because of testing-center cancellations. They form a large share of college-bound seniors in the Class of 2021. The College Board hopes to expand capacity in the fall, but how much that will offset this spring’s testing turmoil remains unknown.

Delivering the SAT at home, using electronic proctoring systems instead of the customary method of human eyesight, would be an extraordinary development. The College Board first raised the idea publicly in April, as a backup plan for the fall, but said at the time that it was an “unlikely” scenario.

Jeremy Singer, president of the College Board, told reporters on April 15 that recent advances in remote proctoring and online testing made an at-home exam possible. “If this was four years ago, we could not make this commitment,” Singer said that day. “The technology was not there.”

The ACT testing organization has also said it is planning at-home alternatives for testing if necessary.

The College Board said Tuesday it will continue to develop “remote proctoring capabilities to make at-home SAT possible in the future.”

Critics of the testing organization have been dubious for weeks it could pull off an at-home SAT, especially given the troubles that emerged with the online AP exams.

“The College Board is simply conceding the inevitable," Bob Schaeffer, interim executive director of the National Center for Fair & Open Testing, said in a statement. "The realities were already clear to admissions professionals: many students will not be able to take the SAT (or ACT) this year because of test-site cancellations, and the technical capacity to administer an at-home, e-SAT does not exist (as demonstrated by last month’s Advanced Placement fiasco).”

Registration opened last week for students in the Classes of 2020 and 2021 who do not yet have an SAT score, but some who sought to sign up encountered difficulties. Some states and large school districts also plan to offer the test during the school day in the fall.

ACT and the College Board have faced numerous challenges in recent weeks. The University of California’s Board of Regents voted unanimously last month to phase out the use of the SAT and ACT in evaluating applications from in-state students. Last week, ACT announced the abrupt departure of its chief executive, Marten Roorda, who was replaced on an interim basis by veteran executive Janet Godwin.

Valerie Strauss contributed to this report.