Matomo — Open-Source Privacy-Friendly Analytics
Matomo On-Premise and Cloud setup. CNIL exemption configuration, Tag Manager, custom dimensions, GA to Matomo migration.
Matomo: On-Premise vs Cloud
Matomo is the most widely deployed open-source analytics solution in the world. It comes in two models: On-Premise (self-hosted on your servers) and Cloud (hosted by Matomo in Europe). The choice depends on your technical and governance constraints. Self-hosting offers total control over data, which never leaves your infrastructure, meeting the strictest sovereignty requirements. Cloud simplifies maintenance (updates, backups, scalability) for teams without dedicated DevOps resources.
On-Premise installation requires a standard PHP/MySQL server. For high-traffic sites (over one million pageviews per month), an architecture with a separate database and asynchronous processing queue (queue tracking) is recommended to maintain acceptable performance. Server sizing is often underestimated: Matomo is more resource-hungry than expected, especially when heatmaps and session recording are enabled.
CNIL exemption and privacy configuration
Matomo’s major advantage in France is its eligibility for CNIL consent exemption. By following a precise configuration, you can collect analytics data without a consent banner for this purpose. The conditions are strict: IP anonymization, no cross-processing with other treatments, cookies limited to 13 months, no data transfer outside the EU, and an accessible opt-out option.
The exemption configuration is not a one-click affair. We enable IP anonymization (at least 2 bytes), disable features requiring consent (cross-device User ID, heatmaps, session recording), configure cookie duration, and verify that tracking meets every CNIL requirement point by point. A post-configuration audit validates that each criterion is fulfilled before removing consent for the analytics purpose.
Tag Manager, custom dimensions and migration
Matomo Tag Manager is natively integrated into the solution. Less feature-rich than GTM, it covers common use cases: tag firing on page view, click, form submit, or custom event. For complex setups requiring community templates or advanced variables, GTM often remains preferable, and the two can coexist.
Matomo’s custom dimensions let you enrich collected data with business attributes: customer type, subscription status, content category. They are configured in the interface and fed via the JavaScript tracker or the API. E-commerce tracking follows a standard schema (product, category, price, quantity) with a dedicated report.
Migrating from Google Analytics to Matomo involves an equivalence exercise: GA4 events are mapped to Matomo events, custom dimensions are recreated, and a unified tagging plan is produced. Historical GA data import is not directly possible, which means maintaining access to GA4 data during a transition period for year-over-year comparisons.