While more than 84 million Americans reportedly tuned into the first presidential debate via traditional TV channels, a new bipartisan poll says that voters--particularly millennials-- are increasingly turning to the web for political information.

Twenty-seven percent of voters rely on online updates for the presidential and U.S. Senate race. That is up four percentage points from 2012, according to the poll conducted by Julie Hootkins of Global Strategy Group and Robert Blizzard of Public Opinion Strategies.

The study interviewed 500 undecided voters in New Hampshire, Florida, Nevada, North Carolina from Oct. 13 to Oct. 18. It found that 40 percent reported spending "no time watching any live TV in a given week," according to poll results.

TV viewership dipped eight percent in the past four years, Hootkins and Blizzard found. Yet viewership remains the top "critical resource for information about the election," with more than half of Americans getting their political information that way.

During the debates, Americans combined mediums, with the majority of undecided voters watching a televised broadcast while using another screen; 57 percent went online during a debate to see what fact checkers were saying and 54 percent went online to personally fact-check.