Most landing pages are published and then forgotten, and most of the money spent driving traffic to them is quietly wasted. Landing page testing is the discipline of measuring which version converts better using controlled experiments.
Why It Matters
Every percentage point of conversion rate improvement compounds across your entire ad spend. At a 2% conversion rate with a $5 CPC, your effective CPA is $250. Improve that rate to 4% and CPA drops to $125, giving you double the customers on the same budget.
Types of Tests
The three most common approaches each suit different situations:
- A/B test: two versions of a page with a single element changed, making results easy to interpret[1]
- Multivariate test: multiple elements changed simultaneously using factorial design, useful when you suspect interactions between variables[2]
- Redirect test: entirely different page URLs, best for testing radically different designs or layouts[3]
What to Test
Start with the elements that have the largest impact on conversion:
- Headlines and subheadlines
- Call-to-action copy, color, and placement
- Page layout and content hierarchy
- Form length and number of fields
- Social proof (testimonials, logos, review counts)
- Hero images and video
How to Run a Test
A disciplined process keeps results trustworthy:
- Write a hypothesis that includes the observation, proposed change, and predicted outcome
- Calculate the required sample size before launching, typically 3,000 to 5,000 visitors per variant[4]
- Let the test run to 95% statistical significance and resist the urge to stop early[5]
- Document every result, win or lose. Losing tests are just as valuable because they narrow the search space
Common Mistakes
Most testing programs fail for the same handful of reasons:
- Changing too many elements at once in an A/B test, which makes it impossible to attribute the result
- Ending tests too early because an early winner looks convincing, known as the "peeking problem"[6]
- Running tests without a hypothesis, which turns experimentation into guessing with extra steps
How Site Scanner Helps
Before launching any test, run a Site Scanner audit and fix technical issues like slow LCP or high CLS. If the underlying page experience is broken, your test results will reflect that noise rather than the variable you actually changed.