Conversion rate

A key indicator that measures the proportion of visitors who have completed a desired action on a website or application. This action can be a transaction, a sign-up, the download of content, a contact request, or any other action defined as a conversion goal.

It is calculated using the following formula:
Conversion rate (%) = (Number of conversions ÷ Total number of visitors) × 100

Why it's a core KPI:

The conversion rate is one of the most representative indicators of a site's business performance. It measures the site's ability to turn traffic into tangible value. It allows you to:

• Evaluate the effectiveness of user journeys,
• Measure the impact of acquisition or activation campaigns,
• Prioritize optimization actions (CRO, UX, content, funnel, etc.),
• Maximize marketing ROI without necessarily increasing traffic.

Examples of conversions:

• E-commerce: purchase, add to cart, subscription to an offer,
• SaaS: free trial sign-up, demo request, paid subscription,
• Lead generation: filling out a form, downloading a white paper,
• Media content: newsletter sign-up, account creation, full viewing.

Contextual interpretation:

A conversion rate must always be analyzed in context, because:

• It varies according to traffic source, device, page type or user segment,
• It can be influenced by traffic quality (e.g., organic vs paid visits),
• It must be assessed alongside other indicators such as:
  • the bounce rate,
  • the average session duration,
  • the browsing depth,
  • or even the revenue per visitor (RPV) for a more comprehensive business reading.

Conversion rate optimization (CRO):

Improving this rate relies on a data-driven approach, including:

• Landing page optimization (visual hierarchy, CTA, loading speed…),
• Behavioral analysis via heatmaps, replays, VoC surveys,
• Implementing A/B tests or multivariate tests to validate changes,
• Segmentation by channel, device or visitor type.