How The World Votes is a super-impressive interactive from Al Jazeera.
It compares tons of elements related to voting in countries around the world, including voting age and structure of the governing system. A small portion of all the info relates specifically to 2019 elections, but the vast majority of the site is not specific to this year.
It would be a good companion site to Constitute, another amazing resource that allows you to compare different constitutions used by countries around the world.
And for even more tools for comparing countries, check out these “Best” lists: