Best Free Diagram Software

Cloudairy is a modern collaboration platform that simplifies the way teams visualize, share, and manage information. Designed for distributed teams and dynamic workflows, Cloudairy offers seamless cloud-based collaboration with real-time editing, version control, and secure sharing capabilities. Whether you're building flowcharts, documents, or templates, Cloudairy brings clarity to complexity and keeps your workspaces organized and actionable. Trusted by agile teams and professionals across industries, Cloudairy accelerates productivity through intuitive tools and deep integration with your favorite cloud services. From brainstorming to delivery, we help you work faster, communicate clearly, and scale effortlessly. Start collaborating with Cloudairy today — where your ideas take flight.

Heptabase empowers you to visually make sense of your learning, research, and projects. To truly make sense of what you've learned, visualize your notes with whiteboards, sections, and mindmaps. Bring all your highlights, annotations, PDFs, journals, and research notes together to discover new insights. Manage complex projects with clarity and flexibility by using powerful tags and properties. And of course, full offline access with blazing-fast speed. Sync and access your notes across unlimited desktop devices, mobile devices, and web browsers. Access all notes and files without an internet connection. Search, load, and edit your notes with blazing-fast speed. Heptabase is a visual note-taking software specifically designed to help you learn and research complex topics, establishing a deep understanding of things you care about. The design of Heptabase focuses on helping you better "understand the topics you care about," rather than simply "taking more notes."

PlantUML is a powerful and flexible open source tool that allows users to create UML diagrams using simple text descriptions. It supports various diagram types, including sequence, use case, class, component, state, and activity diagrams. PlantUML also extends beyond traditional UML with support for other diagram types such as Gantt charts, mind maps, and entity-relationship diagrams. The platform uses a straightforward syntax to generate high-quality diagrams, making it easy for developers, system architects, and project managers to visualize complex systems and processes. Users can export diagrams in multiple formats like PNG, SVG, LaTeX, and ASCII art. PlantUML is compatible with a range of tools and integrates seamlessly into documentation workflows, enhancing productivity for teams and individuals.

yEd makes diagram creation easy and fun with its powerful features and intuitive user interface. yEd is a powerful desktop application that can be used to quickly and effectively generate high-quality diagrams. Create diagrams manually, or import your external data for analysis. Our automatic layout algorithms arrange even large data sets with just the press of a button. yEd comes with an extensive palette of beautiful, ready-to-use elements to get you started with your first diagrams. yEd provides powerful functionality for the layout of complex data sets. Its highly sophisticated mathematical layout algorithms can be used either to automatically arrange diagram elements, or to support you when undertaking a manual layout.