Conversion rate optimisation and testing

Analytics tells you that 97 visitors in 100 left without enquiring. Conversion rate optimisation is the work of finding out why and testing a change. The tools split into two jobs: diagnosis (heatmaps, session recordings, on-page surveys, chat transcripts) shows where and why people get stuck; testing (A/B and multivariate tests, landing page variants) proves whether a change helped.

Start with the question

The traffic problem

Most small sites do not have the traffic to A/B test small changes. At a 3% conversion rate, detecting a 20% relative lift with 95% confidence and 80% power needs roughly 14,000 visitors per variant. Below that, test bold changes (a new offer, a new page) rather than button colours, and lean on diagnosis tools instead. Check your numbers with the A/B test calculator and the conversion rate calculator before you start.

What to set up on day one

1. Track the conversion itself as a GA4 key event, so every tool is judged against the same outcome. See how to track form submissions and leads.
2. Install a free heatmap and recording tool on the pages that matter and watch 20 to 30 sessions before forming a hypothesis.
3. Write each test down: the change, the metric, the minimum sample, the stop date. Stopping when a result looks good inflates false wins.
4. Mask form fields and personal data in recordings, and cover recording tools in your consent banner where the law requires it.

Compare the options in best heatmap and CRO tools, best landing page builders and best live chat software, and read heatmaps and session recordings explained.