Twitter and Pinterest are taking new steps to root out voting misinformation designed to suppress participation in the November elections.

Twitter unveiled a new tool Wednesday that will make it easier for users in the U.S. to report tweets containing misleading information about registering to vote or casting a ballot. The platform said the tool would be available at "key moments" throughout the election.

Pinterest, meanwhile, announced that it will remove posts that include false information about where, how and when people can register to vote or cast a ballot.

Most of the big social media...