How do you figure out the pH level in cleaning products like Windex?

or any kind of cleaning solution that you would have at home...





ex. i have windex, mr clean, chlorox, i don't know what else...





I need to figure this out for an item for my biology lab experiment.How do you figure out the pH level in cleaning products like Windex?
You could use litmus paper which is readily purchased at pharmacies or hardware stores or online (see first ref below).





But many household products have MSDS sheets available on-line (second ref below). Windex lists its pH as 11 in that link.How do you figure out the pH level in cleaning products like Windex?
1) pH paper


2) Add Universal Indicator


3) Add Red Cabbage Juice