Open-source alternatives offer extensive customization through public code access. Most of them provide free / paid cloud service. Some might require self-hosting to use.
An open-source, flexible digital whiteboard that enables quick, intuitive, and collaborative hand-drawn style diagrams and visual thinking
Excalidraw is a free, web-based drawing tool that specializes in creating hand-sketched looking diagrams and collaborative visual representations. Its minimalist interface allows users to rapidly generate diagrams, wireframes, and conceptual sketches with a unique, organic aesthetic that mimics hand-drawn illustrations.
An open-source, interactive digital whiteboard platform designed to enhance teaching and learning through intuitive, collaborative drawing and annotation tools
OpenBoard is a free, cross-platform interactive whiteboard software specifically developed for educators, enabling teachers to create dynamic, engaging digital lessons. Its comprehensive toolset allows for real-time drawing, annotation, and multimedia integration directly within classroom presentations.
An open-source, minimalist web-based drawing and collaboration platform for seamless visual communication and interactive brainstorming
Whitebophir is a lightweight, browser-based collaborative whiteboard that allows multiple users to draw, sketch, and interact on a shared infinite canvas. Its simple, intuitive interface enables real-time collaboration without requiring user registration or complex setup.
Organize, visualize, and connect ideas in an open-source platform with privacy-first design and offline accessibility
Affine is a versatile knowledge management app combining note-taking, drawing, and planning tools in one place. It lets users organize content in blocks, manage tasks, and visualize concepts on whiteboards, all while syncing across devices. The open-source nature allows users to customize and adapt the workspace as needed.
If you are looking for more features or an enterprise solution, you might want to consider closed source alternatives. Some of them has decent free tier.
Intuitive digital whiteboard that empowers teams to visually explore ideas, map out workflows, and collaborate in real-time from anywhere
FigJam is Figma's collaborative whiteboard tool that seamlessly integrates with the Figma design platform. It provides a freeform digital canvas where teams can ideate, plan, and brainstorm together. Users can add a variety of visual elements such as sticky notes, diagrams, illustrations, and frameworks to the whiteboard.
An online whiteboard and collaboration platform that enables teams to visually communicate, brainstorm, and work together on projects in real-time
Miro is a versatile online whiteboard platform that allows teams to collaborate, ideate, and organize their work in a visual, freeform environment. The platform provides a digital canvas where users can create, share, and interact with a variety of visual elements such as sticky notes, diagrams, flowcharts, and more.
Collaborative digital whiteboard for remote and hybrid teamwork