What is conversion rate optimisation?
Conversion rate optimisation, often abbreviated to CRO, is about getting a larger share of the visitors to your website to take the action you want. That could be anything from a purchase in your online shop to a newsletter sign-up or a completed contact form. In other words, conversion rate optimisation is about making better use of your traffic, so you don't just get more visitors, but also more who actually do something that creates value for your business.
Conversion rate optimisation is an ongoing process in which you use data to understand how visitors interact with your site. You analyse where they drop off and how you can remove friction from their experience. The goal is to improve the user journey step by step until it's as easy and motivating as possible to complete the desired action. In many cases, you work alongside efforts such as SEO and digital design, because they affect how users experience the site and, in turn, the conversion rate.
How do you use conversion rate optimisation?
You use conversion rate optimisation by systematically testing what works best for your users. It starts with data. You gather insights through tools such as Google Analytics, heatmaps and user surveys. They show where users click, where they stop and which elements on the page need improving. You then develop hypotheses about what you can change to create a better experience and more conversions.
The classic method is A/B split testing, where you show two versions of a page — for example with different headings, buttons or images — to two segments of your traffic. Once you have enough data, you can see which version performs best. This iterative approach means you keep learning what works for your particular audience, and you can use the results to adjust everything from CTAs to the checkout flow. It's just as important to ensure a consistent experience across channels, so your paid content on social media or Google Ads matches what users find when they land on your website.
Why you should use conversion rate optimisation
Conversion rate optimisation makes a measurable difference, because it improves the impact of the traffic you already have. When you increase your conversion rate, you make better use of your marketing budget. You get more out of every penny you spend on ads, because you don't necessarily need to increase traffic to get more sales. That means lower acquisition costs and higher ROI across your campaigns.
In other words, conversion rate optimisation makes it cheaper to win more customers without increasing your media spend. At the same time, you increase user satisfaction, because users encounter fewer barriers along the way. The easier it is to understand, navigate and buy on your website, the greater the chance they'll do it again next time.
What types and variants are there?
A distinction is often made between two main types of conversion: micro-conversions and macro-conversions. Micro-conversions cover the smaller but significant steps that lead towards a purchase — e.g. signing up for a newsletter or watching a product video. Macro-conversions are the actions with direct business value, such as completing a purchase, filling in a quote request form or booking a meeting.
You can work with both types across digital platforms, whether it's your website, an app or a campaign page. Each platform has its own mechanisms, but the principles of optimisation are the same: find the barriers, test hypotheses and measure the results. In practice, this work is often closely linked to branding and UX design, because the visual style and perceived usability play a central role in conversions.
How do you use conversion rate optimisation in practice?
Conversion rate optimisation typically begins with an analysis, often called a CRO audit. Here, you identify opportunities and challenges in the most important parts of the user journey. You can start by defining which actions count as conversions and how you measure them. You then set specific KPIs, e.g. what percentage of your visitors should fill in a form or complete an order.
Here's the basic formula for conversion rate:
An example can illustrate the difference:
In practice, you continuously test improvements with A/B tests, target your messages with remarketing and adapt the user experience based on the feedback you collect. By combining your CRO data with insights from SEO, social media marketing and paid traffic, you can build a holistic understanding that helps your results grow over time.
What should you watch out for?
Conversion rate optimisation requires patience and a systematic approach. It's tempting to make lots of changes at once, but you should only change one element per test, so you can trust the data. Also make sure you have enough traffic and conversions to make your results statistically valid. A testing tool can give you quick insights, but the quality of your conclusions depends on data reliability and time frame.
You also need to remember that successful optimisation isn't just about numbers. It's just as much about understanding users' intentions and motivating them with relevant content, clear messages and a design that feels intuitive. When you combine your analyses with good content and a well-thought-out user experience, conversion rate optimisation has its greatest impact.
