To understand how long the test should be running, use the calculator
. On average, you can compare the results after 10 000 visits or 100 conversions. Regardless of the number of visits, the test should be conducted for 7 days at least, because user behavior is different on different days of the week.
During testing, don't do anything that might affect the results. Don't send out newsletters or create advertising campaigns as these actions can affect the volume of traffic.