A/B testing, or split testing, compares two versions of the same thing, version A and version B, by showing each to a comparable group of people. The version with the better result on the metric you chose wins.
It replaces opinions with evidence. Instead of guessing which headline, image, price or subject line works, you measure it, and small wins add up over many tests.
- Ads: test hooks, angles, formats and offers. Meta and Google Ads have built-in tools to split a budget fairly.
- Landing pages: test headlines, images, the order of sections and the call to action.
- Emails: test subject lines, send times and offers.
- Competitors' tests: the Brand Tracker groups a tracked brand's creative tests by launch day, so you can see what others are trying.
Good practice: choose the metric before you start, change one variable at a time, run both versions over the same days, and wait until each has enough conversions to trust.
Common mistakes: stopping a test as soon as one version pulls ahead, testing changes too small to matter, and reading a result from a few dozen visitors. Early leads often vanish as more data arrives.