A method of executing an A/B test includes, during execution of the A/B test, determining, by a processing device using a sequential frequentist test, that a sample ratio mismatch has occurred, wherein the sample ratio mismatch is determined before the A/B test ends the execution. The method further includes, in response to the determining, ending the execution of the A/B test before a previously scheduled end of the A/B test.

A method of executing an A/B test includes configuring the A/B test to comprise a first plurality of users in a control group and a second plurality of users in a test group, wherein the first plurality of users and the second plurality of users are to be provided two different versions of a webpage. The method further includes, while the A/B test is executing, determining, by a processing device, that a sample ratio mismatch corresponding to the second plurality of users has occurred, wherein the sample ratio mismatch is determined before the A/B test ends executing. The method further includes, in response to the determining, ending the executing of the A/B test before a previously scheduled end of the A/B test.