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What Is Conversion Rate Optimisation (CRO)?
Conversion
Updated 18 September 2026
Quick Answer
Conversion Rate Optimisation (CRO) is the practice of improving a website to increase the percentage of visitors who complete a desired action — through testing and refining elements like copy, layout, and calls-to-action.
CRO vs. Conversion Rate — What's the Difference?
| CRO | Conversion Rate | |
|---|---|---|
| What it is | The ongoing practice of improving conversion rate | The specific percentage metric being improved |
Why It Matters
- Improving conversion rate is usually cheaper than acquiring more traffic — the same visitors, converting more often.
- Small, specific changes (a clearer headline, a shorter form) can meaningfully move results without a full redesign.
How It Works
- Identify where visitors are dropping off, using analytics.
- Form a hypothesis about why (confusing copy, a long form, a weak CTA).
- Test a change and measure whether conversion rate actually improves.
Key Takeaways
- CRO is the ongoing practice of improving conversion rate through testing and refinement.
- It's often cheaper than acquiring more traffic to get the same results.
- Start with high-traffic pages and a clear hypothesis about what's causing drop-off.
Frequently Asked Questions
What's a realistic CRO improvement to expect?
It varies hugely by starting point and change made — the discipline of testing matters more than expecting a specific number upfront.
Do I need A/B testing software for CRO?
It helps for rigorous testing, but even simple before/after comparisons over time can surface obvious wins.
What should I optimize first?
Your highest-traffic pages with the clearest conversion goal usually offer the best return on effort.