draw.io — Free Open-Source Diagramming Tool for Any Platform

Introduction

draw.io (also known as diagrams.net) is a free, open-source diagramming tool that runs in the browser or as a desktop application. It was created to give teams a no-cost, no-account-required alternative to commercial tools like Lucidchart or Visio.

What draw.io Does

• Creates flowcharts, UML diagrams, ER diagrams, network topologies, and org charts
• Stores files locally, on Google Drive, OneDrive, Dropbox, or GitHub
• Provides 100+ built-in shape libraries for AWS, Azure, GCP, Cisco, and more
• Exports to PNG, SVG, PDF, VSDX, and XML formats
• Integrates with Confluence, Jira, VS Code, and Notion via official plugins

Architecture Overview

draw.io is a pure JavaScript client-side application built on the mxGraph library. The entire editor runs in the browser with no server-side processing of diagram data. The desktop version wraps the web app in Electron, giving native file-system access and offline capability. Storage integrations use OAuth to connect directly from the browser to cloud providers.

Self-Hosting & Configuration

• Deploy the web editor on any static file server or Nginx instance
• Run the Docker image: docker run -d -p 8080:8080 jgraph/drawio
• Configure CSP headers for enterprise lockdown of storage backends
• Customize default libraries and templates via XML configuration files
• Enable server-side PDF export by adding the export server container

Key Features

• Completely free with no feature gating, watermarks, or usage limits
• Works fully offline in the desktop version
• Real-time collaboration when paired with Google Drive or Confluence
• Keyboard-driven editing with extensive shortcut support
• Version history and diff support when stored in Git

Comparison with Similar Tools

• Lucidchart — polished collaboration but requires a paid subscription for teams
• Visio — deep Windows integration but expensive and Windows-only
• Excalidraw — great for hand-drawn style but lacks formal diagram shape libraries
• Mermaid — text-based diagrams ideal for docs but no visual drag-and-drop editor
• PlantUML — code-driven UML generation but steeper learning curve for non-developers

FAQ

Q: Is draw.io really free for commercial use? A: Yes. The core editor is Apache 2.0 licensed and free for any use, including commercial.

Q: Can I self-host draw.io for my organization? A: Yes. Deploy the Docker image or serve the static files from your own infrastructure. No license key needed.

Q: Does draw.io support real-time collaboration? A: Collaboration requires a shared storage backend like Google Drive or Confluence. The editor itself does not include a real-time sync server.

Q: How does draw.io compare to Excalidraw? A: draw.io is better suited for formal technical diagrams (UML, AWS architectures) while Excalidraw excels at informal whiteboard-style sketches.

Sources

• https://github.com/jgraph/drawio-desktop
• https://github.com/jgraph/drawio
• https://www.drawio.com/doc/