What category will my transaction be?
Another useful tool that I've recently come across is a Visa search that helps you figure out what official category the charges from a specific merchant will code to on your Visa statement.
Since many cards have category bonuses (e.g., groceries, gas, dining), this can be helpful to figure out which card to use at various merchants. It's especially helpful if it's a merchant you've never been to and you don't have any historical data in your own account to look back on.
Check it out!