 As the number of open science mandates have been increasing across countries and scientific fields, so too has the need to track open science practices and uptake in a timely and granular manner. The Open Science Observatory Service showcases a collection of indicators and visualizations that help interested stakeholders better understand the open science landscape and contribute to EOSC and UNESCO monitoring. Open Science Observatory visualizes statistics about the open access, repositories, journals, publications, datasets, software, and other research products in Europe across and within country comparisons. It is a service for funders and policymakers, research-performing organizations, providing information for more than 44 country-specific open science statistics. Open Science Observatory allows you to reveal hidden opportunities of a country by exploring trends and breakdown by organizations, data sources, and funders. Evaluate your open science uptake by benchmarking with other European countries. Spot potential collaborations with the pioneers. Print, download, and view statistics in multiple formats. Open Science Observatory is based on the open science principles of openness and transparency, coverage and accuracy, clarity and replicability, readiness and timeliness, trust and robustness. All the information is extracted by the open-air graph, one of the largest open scholarly record collections worldwide. Open Science Observatory is accessible openly on a web portal. It offers a rich set of open science indicators tracking open access research activities. The indicators are shaped together with a community to ensure quality and relevance. Open Science Observatory, your open science statistics and visualization service. Observe the European open science landscape. Browse now.