Best Free Diagram Software 2026: 6 Options Compared
Best free Diagram Software compared: draw.io (diagrams.net), yEd Graph Editor, Excalidraw, Mermaid and 2 more, with free-plan limits, platforms and prices from official pages checked October 23, 2026.
•3 min read•Graphic Design & Diagramming
Quick comparison
| Tool | Price | Platforms | Best for | Tested |
|---|---|---|---|---|
| draw.io (diagrams.net) | Free (Free with no sign-up; open files from local storage or your own cloud account) | Web, Windows, macOS, Linux | General diagramming with no limits | Docs only |
| yEd Graph Editor | Free (Free including commercial use; may not be redistributed or used in automated processes) | Windows, macOS, Linux (Java) | Automatic layouts of large graphs | Docs only |
| Excalidraw | Free (Free web app with real-time collaboration and end-to-end encryption); paid from $6 per user/month, Excalidraw+ | Web | Sketchy diagrams for discussion | Docs only |
| Mermaid | Free (Open-source library plus free online Mermaid Live Editor) | Web, JavaScript library | Diagrams kept next to code | Docs only |
| tldraw | Free (Free whiteboard web app with instant collaboration; no paid plan or limits shown on the homepage) | Web | Quick shared sketches | Docs only |
| Lucidchart | Free (3 editable Lucidchart documents, 75 shapes per document, 100 templates); paid from $9 per month, billed annually (Individual) | Web | Polished diagrams with templates | Docs only |
Independent comparison. Paid placements are labelled separately; editorial links earn no affiliate commissions. Learn more.
Good fit if
- You want a free general-purpose editor (draw.io (diagrams.net) is the pick)
- Your diagrams live in documentation (Mermaid is the pick)
- You lay out big graphs automatically (yEd Graph Editor is the pick)
- You want a quick collaborative sketch (Excalidraw is the pick)
- You need a templated business diagram (Lucidchart is the pick)
Not ideal if
- You need paid-tier features, uptime guarantees or support that these free plans leave out
Diagram software splits into drag-and-drop editors, whiteboards and text-based tools, and the best free option depends on how often you will revise the picture. draw.io (diagrams.net) is the default for many people: it is free with no sign-up, Apache-2.0 licensed, and available as a web app and as desktop apps for Windows, macOS and Linux. yEd Graph Editor is a free desktop app for Java that imports Excel and XML and exports PNG, JPG, SVG and PDF, handy for automatic layouts of large graphs. Excalidraw gives a deliberately hand-drawn look with real-time collaboration. tldraw is a free whiteboard on the web. Mermaid generates diagrams from Markdown-like text, so diagrams live in version control next to code. Lucidchart and Miro are polished SaaS products whose free plans cap you at three editable documents or boards. The trade-off is a free canvas that anyone can use versus the limits that hosted products put on files. If your diagrams belong in documentation, choose Mermaid. If stakeholders need to edit them visually, choose draw.io. Always export an editable source file along with the image, because a PNG alone cannot be updated later.
draw.io (diagrams.net)
Apache-2.0, free with no sign-up, as a web app and desktop apps for Windows, macOS and Linux. Files open from local storage or your own cloud account. The home page does not mention Visio import.
Price: Free (Free with no sign-up; open files from local storage or your own cloud account) (draw.io (diagrams.net) pricing, checked 2026-10-22).
Platforms and license: Web, Windows, macOS, Linux. Apache-2.0 (open source).
Project activity: 9k GitHub stars · latest release v32.6.1 (Oct 23, 2026) · last commit Oct 23, 2026
Best for: General diagramming with no limits.
Compare: draw.io (diagrams.net) alternatives
yEd Graph Editor
Freeware (proprietary) for desktop on Java; free including commercial use, but it may not be redistributed or used in automated processes. Imports Excel and XML; exports PNG, JPG, SVG and PDF.
Price: Free (Free including commercial use; may not be redistributed or used in automated processes) (yEd Graph Editor pricing, checked 2026-10-22).
Platforms and license: Windows, macOS, Linux (Java). Freeware (proprietary).
Best for: Automatic layouts of large graphs.
Worth knowing: Imports Excel and XML; exports PNG, JPG, SVG, PDF. Visio export is a separate paid yFiles add-on.
Excalidraw
MIT-licensed free web app with real-time collaboration and end-to-end encryption; Excalidraw+ is $6 per user a month. Hand-drawn look, not a formal shape library.
Price: Free (Free web app with real-time collaboration and end-to-end encryption); paid from $6 per user/month, Excalidraw+ (Excalidraw pricing, checked 2026-10-22).
Platforms and license: Web. MIT (open source).
Project activity: 134.7k GitHub stars · latest release v0.18.1 (Apr 21, 2026) · last commit Oct 27, 2026
Best for: Sketchy diagrams for discussion.
Worth knowing: Excalidraw+ has a 14-day trial; annual billing saves 14%. Hand-drawn look, not a formal-shape library.
Mermaid
MIT open-source library plus a free online Live Editor. Generates diagrams from text; a paid platform exists at mermaid.ai with no price found.
Price: Free (Open-source library plus free online Mermaid Live Editor) (Mermaid pricing, checked 2026-10-22).
Platforms and license: Web, JavaScript library. MIT (open source).
Project activity: 90.9k GitHub stars · latest release @mermaid-js/tiny@12.2.0 (Oct 13, 2026) · last commit Oct 27, 2026
Best for: Diagrams kept next to code.
Worth knowing: Generates diagrams from Markdown-like text. A paid platform exists at mermaid.ai; its price was not found.
tldraw
Free whiteboard web app with instant collaboration; the homepage shows no paid plan or limits. The SDK license is source-available for development use only.
Price: Free (Free whiteboard web app with instant collaboration; no paid plan or limits shown on the homepage) (tldraw pricing, checked 2026-10-23).
Platforms and license: Web. Source-available SDK (development use only without a license key); tldraw.com is a free web app.
Best for: Quick shared sketches.
Worth knowing: Free web whiteboard. The homepage did not state a license for the app or the SDK.
Lucidchart
Free plan: 3 editable documents, 75 shapes per document, 100 templates; Individual is $9 a month billed annually. The vendor page was unreadable, so figures come from secondary listings.
Price: Free (3 editable Lucidchart documents, 75 shapes per document, 100 templates); paid from $9 per month, billed annually (Individual) (Lucidchart pricing, checked 2026-10-23).
Platforms and license: Web. Proprietary SaaS.
Best for: Polished diagrams with templates.
Compare: Lucidchart alternatives
Which one to pick
- You want a free general-purpose editor: draw.io (diagrams.net)
- Your diagrams live in documentation: Mermaid
- You lay out big graphs automatically: yEd Graph Editor
- You want a quick collaborative sketch: Excalidraw
- You need a templated business diagram: Lucidchart
Limits of this review
Docs-only for draw.io (diagrams.net), yEd Graph Editor, Excalidraw, Mermaid, tldraw, Lucidchart: we did not install or run them, so feature claims come from vendor pages. Vendor prices and free limits change; confirm on the linked pricing page before you commit.
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Kevin Fan
Kevin Fan is a SaaS founder. He runs Free Instead Of, which tracks free and open-source alternatives to paid software and checks each price and free-plan limit against the vendor's own pages.
Methodology
Based on official pricing, license and product pages checked between 2026-10-22 and 2026-10-23: draw.io (diagrams.net), yEd Graph Editor, Excalidraw, Mermaid, tldraw, Lucidchart. Prices, free limits and licenses are the figures shown on those pages on those dates. No tool on this page was installed or run. No accounts were created.