Preheat oven to 250F and line two baking sheets with parchment paper.
Arrange oven racks on second lowest and second highest positions.
In clean glass or metal bowl, combine egg whites, Swerve, vanilla, cream of tartar and salt. Beat on medium high until medium stiff peaks form and mixture becomes somewhat glossy. Do not beat until stiff.
Spoon or pipe mixture into 20 to 24 large meringues.
Bake for 18 to 20 minutes at 250F. Then reduce oven temperature to 200F and continue to bake for another 18 to 20 minutes, until crisp and tips are just starting to brown.
Turn off oven and let meringues it inside for 2 hours or longer.