Poll shows Obama and Romney tied three days before election
Of likely voters polled nationally, 47 percent said they would back Obama, the Democratic incumbent, while 46 percent said they would back Romney, the former Massachusetts governor.
The results fall within the poll's credibility interval, a tool used to account for statistical variation in Internet-based polls.
The two men have been locked in a tight race for weeks. Both are doing final swings in battleground states over the weekend, trying to sway a small group of remaining undecided voters and to encourage their supporters to get to the polls.
The precision of the Reuters/Ipsos online polls is measured using a credibility interval, which in this case is plus or minus 3.4 percentage points for likely voters.