Draw.io - Free Diagramming That Doesn't Suck

Draw.io is what happens when someone builds diagramming software for actual humans instead of corporate purchasing departments. JGraph Ltd started the mxGraph project in 2005, which became Draw.io around 2012. So it's been around 13 years or so without selling out or going freemium. Pretty remarkable in today's SaaS hellscape.

The Technical Reality

Here's the thing that makes Draw.io different: it runs entirely in your browser. No server bullshit. When you open a diagram, all the processing happens on your machine. The Draw.io team doesn't see your data because it never hits their servers. This isn't marketing speak - I've watched network traffic and confirmed it.

This client-side architecture means you can work offline, your company's IT security team won't freak out, and you're not locked into someone else's platform. Files are stored as XML, so you can diff them in Git, parse them with scripts, or migrate to something else if you need to.

Runs in everything: Chrome, Firefox, Safari, Edge - even that ancient IE your company somehow still uses. No plugins, no downloads, just works.

Integrations That Actually Work

I've tested most of these integrations in real projects:

• Confluence and Jira: Embed diagrams directly in pages. Beat the shit out of paying $15/user/month for Lucidchart just to draw a flowchart. Latest version supports Jira Software 10.0 with automatic dark theme switching.
• Google Drive, OneDrive, Dropbox: Store files wherever you want. Real-time collaboration works when multiple people have the file open.
• GitHub and GitLab: Version control for diagrams. Treat documentation like code, which is how it should be.
• VS Code extension: 3.2M downloads on marketplace. Edit .drawio files right in your editor. Feels native.

Real-World Use Cases from My Experience

Built architecture diagrams for microservices migrations. Created database schemas that the frontend team could actually understand. Drew network topology diagrams when our AWS setup got too complex for anyone to remember. Documented API workflows for onboarding new developers.

The shape libraries cover everything: AWS icons, Azure services, GCP components, UML shapes, network equipment. New in 2025: the Network 2025 shape library with customizable shadows and enhanced styling options. If you need something specific, you can import custom shape libraries or draw your own.

One gotcha I've hit: collaboration gets messy if someone closes their browser while others are editing. File locks up until the connection times out, which can be anywhere from 2-10 minutes. Still beats paying Miro $10/month per user though.

The Best Part: It's Actually Free

Not "free trial" or "free tier with limits." Just free. No watermarks, no file limits, no bullshit. The official app works perfectly and costs nothing. They make money from enterprise Atlassian integrations, not from screwing over individual users.

After using Draw.io for documenting everything from microservices architecture to database schemas, here's what it's actually good at and where it makes you want to punch your monitor.

The Stuff It Handles Really Well

Architecture and System Design:
Built dozens of microservices diagrams with the AWS shape library. The icons look professional and clients don't realize you drew them in a free tool. UML support is solid - class diagrams, sequence diagrams, the works. Not as fancy as Enterprise Architect but good enough for 99% of use cases.

Database Documentation:
Entity relationship diagrams that don't make your eyes bleed. Drag tables, connect relationships, export to PNG for wiki pages. Saved my ass when documenting a legacy database with 200+ tables that nobody understood. The database template gets you started fast.

Network Topology:
Cisco, AWS, Azure icons all included. Drew our entire network infrastructure when we had that outage and nobody could remember where anything was connected. Much faster than Visio and doesn't cost $300 per license.

Process Flows:
BPMN 2.0 compliance if you're into that corporate process mapping stuff. Flowcharts for decision trees. Works great for documenting deployment processes or troubleshooting workflows.

Where It's Frustrating As Hell

Interface Improvements (2025):
Draw.io got a modernized interface update in March 2025 to match Google Drive's streamlined design. The toolbar is still cluttered but cleaner than before. The new omnibox search provides quick access to shapes, tools, and options. First hour using it, you'll still find the UI overwhelming but it's getting better.

Collaboration Weirdness:
Real-time editing works until it doesn't. Someone closes their browser mid-edit and the file gets locked for 10 minutes. No proper conflict resolution - if two people edit the same element, last save wins. Better than nothing but not as smooth as Google Docs.

Mobile Experience:
Forget using it on your phone. Barely functional on tablets. If you need to edit diagrams on mobile, use something else or wait until you're back at a computer.

Performance with Large Diagrams:
Once you hit 100+ elements, it starts getting sluggish. Not terrible but noticeable. Had to break one large architecture diagram into multiple files because rendering got slow.

The Formats and Export Reality

Files save as .drawio XML format. Can export to PNG, JPG, PDF, SVG, HTML. The SVG exports are clean and scale well. PDF exports look professional for presentations. HTML exports are weird but sometimes useful.

Here's a gotcha: if you store files in GitHub, you can make them .drawio.svg files that render directly in README files. Pretty clever.

Custom Shapes and Libraries

You can import custom shape libraries or create your own. Did this for company-specific icons and logos. Not trivial but doable if you know SVG. The community libraries cover most cloud services and networking equipment.

Integration Reality Check

The Confluence plugin works perfectly. Diagrams embed directly in pages and you can edit them inline. Saved our team probably $2000/year vs paying for Lucidchart licenses.

GitHub integration lets you store diagrams right in your repo with your code. Version control for documentation - finally. GitLab works the same way.

The VS Code extension is legit useful. Edit .drawio files without leaving your editor. Feels native, works offline, supports themes.