To capture the White House, a candidate must amass at least 270 votes in the Electoral College. Edison Research gave Biden a 253-214 lead over the incumbent.
Here is the state of play in the five states. The vote counts are supplied by Edison Research.
PENNSYLVANIA (20 electoral votes)
Biden has a lead of 19,584 votes, or a 0.3 percentage point margin, as of 7.30 p.m. ET (0030 GMT), with 96% of the estimated vote counted. Under Pennsylvania law, a recount is automatic if the margin of victory is less than or equal to 0.5 percentage point of the total vote.
There are still ballots to be counted in Philadelphia, the state’s largest city, and Allegheny county, home to Pittsburgh, which started to report votes on Friday evening.
The majority of ballots left in Philadelphia are provisional and military ballots, Pennsylvania’s election commissioner said, adding the final count could take several days.
Friday is the last day that Pennsylvania can accept mail-in ballots postmarked on or before Election Day.
GEORGIA (16 electoral votes)
Biden leads Trump by 4,022 votes as of 7.30 p.m. ET (0030 GMT), with 99% of the estimated vote counted. Trump needs both Pennsylvania and Georgia to win a second term.
Brad Raffensperger, Georgia’s secretary of state, said he expects the margin to be just a few thousand votes, which will likely trigger a recount. A recount must wait until Georgia’s results are certified, expected on or before Nov. 20.
About 9,000 military and overseas ballots are still outstanding and could be accepted if they arrive on Friday as long as they were postmarked Tuesday or earlier.
ARIZONA (11 electoral votes)
Biden has 49.8% versus Trump at 48.7%, a lead of 36,835 votes, with 94% of the expected vote tallied as of 7.30 p.m. (0030 GMT).
The state has about 250,000 to 270,000 ballots left to count and will give an update at around 9 p.m. ET, Arizona Secretary of State Katie Hobbs told CNN earlier on Friday.
NEVADA (6 electoral votes)
Biden leads Trump by 22,657 votes, or 1.8 percentage points, with about 93% of the vote counted.
More votes are expected out of Clark county, which includes Las Vegas. The majority of mail-in ballots are expected to be counted by Sunday, according to local officials.
NORTH CAROLINA (15 electoral votes)
Trump leads by 76,526 votes, or 1.4 percentage points, with about 98% of the estimated vote counted.
State officials have said a full result will not be known until next week. The state allows mail-in ballots postmarked by Tuesday to be counted if they are received by Nov. 12. Reporting by Leela de Kretser and Tiffany Wu; Editing by Leslie Adler