Nelio A/B Testing includes multiple types of experiments, and (usually) you can run them all at the same time. Thus, for instance, you can run two page experiments on two different pages at the same time, you can run a headline experiment and a CSS experiment, and so on. However, we implemented a couple of limitations that you should be aware of:
You cannot run multiple tests on the same element at the same time. Thus, for instance, you cannot run two experiments on the landing page at the same time, or you cannot run two theme experiments at the same time. If you think about it, that makes complete sense: if you’re testing your WordPress’ front page with two different tests, and a user lands on that page, which alternative should she see?
You cannot run global experiments at the same time. Global experiments include CSS, Menu, Theme, and Widget experiments. A global experiment impacts all the pages on your website (that’s why sometimes we call them “global experiments”) and, for the sake of simplicity, we decided that you can only run one global experiment at a time. Why? Well, think about a Theme experiment. Each alternative theme might define its own (alternative) menus or widgets, and have its own CSS rules… It doesn’t make sense to run them all at the same time, doesn’t it?