InteractiVenn is a web-based tool for analyzing sets using Venn diagrams, supporting up to six sets. It offers an intuitive interface for constructing Venn diagrams and allows analysis of set unions while preserving the diagram's shape. The tool enables users to explore set unions through a tree or list, and to save, load, and export diagrams in various formats. It also allows users to view elements in specific regions of the diagram and adjust visual settings. InteractiVenn was tested on two biological datasets. In the first case, it was used to compare feature selection methods for identifying candidate biomarkers in prostate cancer proteomic data. The tool helped identify proteins that were uniquely or commonly found across different methods, revealing insights into their potential as biomarkers. In the second case, it was used to analyze the distribution of gene families among six plant genomes, showing how gene families are shared or unique among different species. InteractiVenn provides a flexible way to explore set unions, allowing users to navigate through different levels of union operations. It supports both hierarchical (tree) and non-hierarchical (list) approaches to union operations, enabling users to gain different perspectives on the data. The tool is freely available online at www.interactivenn.net and is designed for use in a wide range of scientific fields, including biology, bioinformatics, and data analysis. It is implemented as a web application using HTML, JavaScript, and various libraries, and is compatible with modern web browsers. The tool is open-source under the GPLv3 license and is available for use by both academic and non-academic users.InteractiVenn is a web-based tool for analyzing sets using Venn diagrams, supporting up to six sets. It offers an intuitive interface for constructing Venn diagrams and allows analysis of set unions while preserving the diagram's shape. The tool enables users to explore set unions through a tree or list, and to save, load, and export diagrams in various formats. It also allows users to view elements in specific regions of the diagram and adjust visual settings. InteractiVenn was tested on two biological datasets. In the first case, it was used to compare feature selection methods for identifying candidate biomarkers in prostate cancer proteomic data. The tool helped identify proteins that were uniquely or commonly found across different methods, revealing insights into their potential as biomarkers. In the second case, it was used to analyze the distribution of gene families among six plant genomes, showing how gene families are shared or unique among different species. InteractiVenn provides a flexible way to explore set unions, allowing users to navigate through different levels of union operations. It supports both hierarchical (tree) and non-hierarchical (list) approaches to union operations, enabling users to gain different perspectives on the data. The tool is freely available online at www.interactivenn.net and is designed for use in a wide range of scientific fields, including biology, bioinformatics, and data analysis. It is implemented as a web application using HTML, JavaScript, and various libraries, and is compatible with modern web browsers. The tool is open-source under the GPLv3 license and is available for use by both academic and non-academic users.