A/B tests are probably the most common type of test that a marketer runs. These are also called split tests, and they compare the conversion rates of two assets (such as an email or landing page) by changing one element at a time.
You can also compare more than two assets by running an A/B/C test or an A/B/C/D test. When starting out with lead testing, however, you should begin with a simple A/B test.
The key here is that you are changing only one variable at a time so you can pinpoint any change in conversion and attribute it to that changed variable. A/B tests are fantastic for testing things like CTA (call-to-action) buttons, copy, headlines, graphics, form length, and email time sent. You can even use A/B testing for social messaging, content format, or webinar frequency.
When using A/B testing, all you do is split your email send, PPC landing page traffic, or post your social messaging at two different times. You should see one asset performing better than the other.
Check out this example:
A/B testing is perfect for testing small numbers of variables at a given time, is easy to grasp, and the data can be seen quickly and clearly. The disadvantage of an A/B test is that it is simplistic, so it can't handle multiple variable changes at a time. In that case, you would use multivariate testing.