A/B testing replaces opinions with evidence. Show two versions to similar groups of people, measure one outcome, and let behaviour decide which version stays.
It is not only for large sites. Any product with steady traffic can learn from a simple test, as long as the question is clear and the result is trusted.
Test One Change at a Time
Change a headline, a button label or a layout, not all three. When only one thing differs, you know what caused the result.
Write your hypothesis first: “If we shorten the form, more people will finish it.” A test without a hypothesis is only a guess with a chart.
Pick one main metric before you start and stick to it. Looking for a win in every number will always find one by chance.
Johan Wick
“A test that proves you wrong is not a failure. It is a mistake you did not ship.”
Wait for Enough Data
Stopping a test early because one version looks ahead is the most common mistake. Decide the sample size before you start and let the test run to the end.
Run it for at least one full week so weekday and weekend behaviour are both included. Traffic on a Monday rarely looks like traffic on a Sunday.
Record every result, including the ones that change nothing. A flat test still tells you where not to spend your time.
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