Feature-rich diagram editor offering privacy-focused, ad-free experience with real-time collaboration, offline usage, dark mode, and cloud storage support. No registration required and compatible with various diagram formats, it excels in simplicity by not tracking user data.

Draw lets you produce anything from a quick sketch to a complex plan, and gives you the means to communicate with graphics and diagrams. With a maximum page size of 300cm by 300cm, Draw is a an excellent package for producing technical drawings, general posters, and much else.

yEd is a powerful diagram editor that can be used to quickly create diagrams manually or import external data for analysis and auto-magically arrange even large data sets by just pressing a button. You can use yEd to quickly create flow charts, BPMN and UML diagrams...

Dia is a GTK+ based diagram creation program for Linux, Unix, Mac OS X and Windows released under the GPL license.

Excalidraw is an open-source whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them. Available directly online as a web app and also through CodeSandbox to easily see how the code works, and the app is available for self-hosting.

Lucidchart is a cloud-based platform that promotes teamwork through diagramming, collaboration, and data visualization. It serves millions worldwide, offering flowcharts, UML, real-time collaboration, Visio support, and browser access. Designed for innovation and understanding, it integrates easily into work...

Create data-connected diagrams with real-time collaboration as part of the Office Suite. Ideal for IT and business professionals, it visualizes complex info with ease, providing intuitive tools for diagramming, mind mapping, and vector graphics.

PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams. The generator can be run anywhere within JVM and integrated with various application such as wiki, text editor, IDE, programming language, documentation generator, and others.

Gephi is the leading visualization and exploration software for all kinds of graphs and networks. Gephi is open-source and free.

Google Drawings, part of Google Drive, allows users to collaborate creating, sharing, and editing images or drawings. It can be used for creating charts, diagrams, designs, flow-charts, etc.

OmniGraffle can help you make eye-popping graphic documents—quickly—by providing powerful styling tools, keeping lines connected to shapes even when they’re moved, and magically organizing diagrams with just one click.

Feature-rich, open-source Wireflow offers a collaborative platform for online creation of complex user flow prototypes. Ideal for team work in UI design, wireframing, and mind mapping, promoting idea sharing in real-time environment aided by modern whiteboard features.