draw.io — Free Cross-Platform Diagramming Tool

Introduction

draw.io (also known as diagrams.net) is a free, open-source diagramming application created by JGraph. It provides a fully-featured diagram editor that works offline as a desktop app via Electron or directly in the browser, with no account required and no data sent to external servers.

What draw.io Does

• Creates flowcharts, UML diagrams, network topologies, ER diagrams, and mind maps
• Provides hundreds of built-in shape libraries for AWS, Azure, GCP, Cisco, and more
• Supports real-time collaboration when connected to cloud storage backends
• Exports diagrams to PNG, SVG, PDF, VSDX, and XML formats
• Integrates natively with Confluence, Jira, Google Drive, OneDrive, and GitHub

Architecture Overview

draw.io is built with a JavaScript-based rendering engine using mxGraph (now jgraph) for vector graphics. The desktop edition wraps the web app in Electron for offline use. Diagram data is stored as compressed XML, and all rendering happens client-side, meaning no server is needed for core functionality.

Self-Hosting & Configuration

• Deploy the web editor with a single static file server or Docker container
• Desktop builds are available for Windows, macOS, and Linux via GitHub Releases
• Configure default storage backends (local, Google Drive, OneDrive, GitHub) at startup
• Custom shape libraries can be loaded from XML files or URLs
• Embed diagrams in wikis and docs using the provided iframe integration

Key Features

• Completely free with no feature gating or premium tiers
• Works fully offline with the desktop app — no internet needed
• Supports dark mode, grid snapping, and multi-page diagrams
• Includes a built-in PlantUML and Mermaid import for text-based diagramming
• Plugin system allows custom shapes, menus, and automation

Comparison with Similar Tools

• Lucidchart — commercial SaaS with team features; draw.io is free and self-hostable
• Excalidraw — hand-drawn style whiteboard; draw.io offers precise technical diagrams
• Mermaid — text-only diagram generation; draw.io adds a full visual editor
• Visio — Microsoft proprietary; draw.io imports/exports VSDX and runs on all platforms
• Penpot — design-focused tool; draw.io specializes in technical and infrastructure diagrams

FAQ

Q: Is draw.io really free? A: Yes. The core application is fully open source under the Apache 2.0 license with no premium tiers.

Q: Where is my diagram data stored? A: Locally on your device by default. You can optionally save to Google Drive, OneDrive, GitHub, or a self-hosted backend.

Q: Can I use draw.io for team collaboration? A: Yes, when diagrams are stored on shared cloud drives, multiple users can edit concurrently.

Q: Does it support version control? A: Diagram files are XML-based and diff-friendly, making them suitable for Git workflows.

Sources

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