Best Diagramming Tools 2026: 10 Free Options Compared
Compare the best free diagramming tools and software in 2026. We tested Draw.io, Lucidchart, Miro, Excalidraw and Canva for flowcharts, UML and mind maps.
Finding the Right Free Diagram Tool in 2026
The tool you choose quietly decides how your afternoon goes. The right one turns an idea into a finished visual in a few minutes. The wrong one has you fighting menus and connectors long after the actual thinking was done. Good news: no matter what you are after, whether that is a business flowchart, a UML model for a codebase, a mind map to untangle a topic, or a clean figure for a research paper, there is a capable tool that costs nothing and fits the way you already work.
To save you from installing and abandoning a dozen apps, we lined up 10 of the strongest free diagramming options and looked at what each one actually does well, where its free plan stops, what an upgrade costs, and the kind of person it suits best.
Text to Diagram Generator
Transform text descriptions into professional diagrams instantly with AI. No drag-and-drop needed, just describe what you want.
Try it free →At-a-Glance Comparison
If you only have a minute, the table below sums up all 10 tools at once. Skim it first, then jump to the full write-ups on whichever names catch your eye.
| Tool | Best For | Free Tier Limits | Collaboration | Export Formats | Open Source |
|---|---|---|---|---|---|
| Figviz | AI-powered diagrams, scientific visuals | Free credits on signup | No | PNG, SVG | No |
| Draw.io (Diagrams.net) | General-purpose diagramming | Unlimited | Yes | PNG, SVG, PDF, XML | Yes |
| Lucidchart | Technical documentation | 3 editable documents | Yes | PNG, PDF, Visio | No |
| Miro | Whiteboarding and brainstorming | 3 boards | Yes | PNG, PDF, SVG | No |
| Excalidraw | Quick hand-drawn sketches | Unlimited | Yes | PNG, SVG, JSON | Yes |
| Canva | Design-focused diagrams | Unlimited designs (limited templates) | Yes | PNG, PDF, SVG | No |
| Creately | Team visual collaboration | 45 items per canvas | Yes | PNG, SVG, PDF | No |
| PlantUML | Code-based UML diagrams | Unlimited | No | PNG, SVG, EPS | Yes |
| Mermaid.js | Developer-friendly diagrams | Unlimited | No (text-based) | PNG, SVG | Yes |
| Google Drawings | Simple diagrams for Google users | Unlimited | Yes | PNG, SVG, PDF | No |
1. Figviz - Best for AI-Powered Diagrams
Where every other tool on this list hands you a blank canvas and a toolbar, Figviz skips the canvas entirely. You type a sentence or two describing the diagram you have in mind, and the AI returns a polished version a few seconds later. There is nothing to drag, snap, or align by hand.
Key Features
- Text-to-diagram generation: Describe your flowchart, mind map, or architecture diagram in natural language
- Multiple diagram types: Supports flowcharts, mind maps, UML, ER diagrams, network diagrams, Venn diagrams, and more
- Scientific focus: Purpose-built for researchers, students, and educators who need publication-quality visuals
- No learning curve: If you can write a sentence, you can create a diagram
Free Tier
Sign up and a batch of free credits lands in your account straight away, which covers several diagrams before you spend anything. When you run low, you can top up through inexpensive credit packs.
Pros and Cons
| Pros | Cons |
|---|---|
| Fastest way to create diagrams | Requires credits for generation |
| No design skills needed | Less manual control than drag-and-drop tools |
| Publication-quality output | Newer platform with growing feature set |
| Multiple export formats (PNG, SVG) |
Best For
People who already know the point they want a diagram to make and would rather not lose an hour arranging boxes to make it. That covers a lot of researchers, students, and busy professionals who value a finished visual over fine-grained manual control.
AI Flowchart Generator
Generate professional flowcharts from text descriptions. Perfect for business processes, decision trees, and workflows.
2. Draw.io (Diagrams.net) - Best Completely Free Option
Ask any long-time diagrammer for a free recommendation and Draw.io, now operating under the Diagrams.net name, is the answer you tend to hear first. What sets it apart is what it does not do: there are no document quotas, no locked premium features, no upsell screens waiting at the edges. The whole thing is simply free, which is rarer in this category than you might expect.
Key Features
- Unlimited diagrams: No cap on documents, shapes, or exports
- Offline support: The desktop app runs without an internet connection
- Cloud storage integration: Save files directly to Google Drive, OneDrive, Dropbox, or your local machine
- Extensive shape libraries: Hundreds of shape sets covering UML, network topology, electrical schematics, floor plans, and beyond
- Import Visio files: Open .vsdx files without a Visio license
Free Tier
There is only one tier, and it includes everything. The core diagramming experience has no paid version sitting above it.
Pros and Cons
| Pros | Cons |
|---|---|
| 100% free with no limitations | Interface looks dated next to newer tools |
| Works offline | Real-time multi-user editing is limited |
| Open source and privacy-focused | No built-in community template marketplace |
| Handles virtually every diagram type | Complex diagrams have a steeper learning curve |
Best For
Pretty much anyone who refuses to pay for a diagramming tool and still wants the full toolset. The depth of its network, UML, and flowchart libraries makes it especially handy for developers and IT teams.
3. Lucidchart - Best for Technical Documentation
Few platforms feel as carefully built as Lucidchart. The interface is smooth, the output looks corporate-ready out of the box, and the free plan gives you a real taste of that polish, which makes it a popular starting point for teams writing technical documentation.
Key Features
- Smart shapes and auto-layout: Shapes align automatically with intelligent snapping
- Data linking: Connect diagram elements to live external data sources
- Extensive integrations: Compatible with Google Workspace, Atlassian, Slack, Microsoft Teams, and more
- Version history: Review and restore earlier versions of any diagram
- Team collaboration: Live co-editing with comments and @mentions
Free Tier
You get 3 editable documents, each holding up to 60 shapes, plus more than 100 ready-made templates and the basics of real-time collaboration.
Pros and Cons
| Pros | Cons |
|---|---|
| Top-tier user experience | Free tier is tightly restricted to 3 documents |
| Excellent for org charts and flowcharts | Paid plans carry a high price tag ($7.95+/mo) |
| Broad integration ecosystem | Some advanced features need the Team plan |
| Professional-quality output |
Best For
Teams whose diagrams have to look formal and on-brand, think documentation sets, process maps, and org charts, and who will not mind paying once three documents stops being enough.
4. Miro - Best for Collaborative Whiteboarding
Calling Miro a diagramming tool undersells it. At heart it is a shared whiteboard built for groups, and diagramming is one of the many things it happens to do well. The moment your process begins with a team kicking ideas around, few alternatives keep up with it.
Key Features
- Infinite canvas: Your workspace has no hard edges
- Real-time collaboration: Multiple contributors work side by side with live cursor tracking
- Diagramming shapes pack: Dedicated shape sets for flowcharts, UML, concept maps, and swimlane layouts
- Pre-made templates: Hundreds of ready-to-use templates spanning diagram types
- Voting and timers: Native facilitation features for workshops and sprints
Free Tier
You can keep 3 editable boards going at once, invite as many teammates as you like, plug in the core integrations, and pull from a starter set of templates.
Pros and Cons
| Pros | Cons |
|---|---|
| Best real-time collaboration | 3-board cap on the free plan |
| Great for workshops and brainstorming | Not optimized for precise technical diagrams |
| Huge template library | Can feel cluttered for straightforward tasks |
| Strong integration ecosystem | Large boards can slow performance |
Best For
Remote and hybrid teams that run workshops, design sprints, or open-ended brainstorms, where the diagram is just one output of a bigger group conversation.
5. Excalidraw - Best for Quick Sketches
Excalidraw leans into a deliberately rough, marker-on-whiteboard look, and that choice is the whole point. By trading crisp geometry for speed and ease, this open-source tool makes it painless to dash off an idea and move on rather than fussing over alignment.
Key Features
- Hand-drawn style: Output looks like whiteboard sketches, which lowers the psychological pressure to make everything perfect
- Real-time collaboration: Share a link and start editing together instantly without needing an account
- Component libraries: Community-built shape packs for common diagramming patterns
- Privacy-first: Collaboration sessions use end-to-end encryption
- Open source: Self-hosting is available for full data control
Free Tier
The main app is free and open source with nothing held back. If you want hosted files, shared team spaces, and richer collaboration, Excalidraw+ is the optional paid layer on top.
Pros and Cons
| Pros | Cons |
|---|---|
| No signup required | Template library is limited |
| Instant collaboration through link sharing | Hand-drawn aesthetic does not suit formal documents |
| Open source and privacy-focused | No built-in support for UML or BPMN notation |
| Extremely fast and lightweight | Export options are fairly basic |
Best For
Engineers and designers who want to throw an architecture sketch, a quick flowchart, or an early wireframe onto the screen mid-meeting or during a code review, without breaking the flow of the conversation.
6. Canva - Best for Design-First Diagrams
Canva did not start out as a diagramming app, it grew into one. Layered on top of a full graphic design suite, its diagram features have matured to the point where, if you care more about how the result looks than about strict notation, nothing else here comes close on sheer visual appeal.
Key Features
- Beautiful templates: Thousands of professionally styled diagram templates ready to customize
- Brand kit: Apply consistent company colors, fonts, and logos across every design
- Drag-and-drop editor: An approachable interface usable by virtually anyone
- Presentation mode: Convert diagrams directly into slide decks without leaving Canva
- Stock photos and icons: Millions of free design assets are included
Free Tier
A free account lets you create as many designs as you want, dip into a generous slice of the template catalog, use basic stock imagery, and store up to 5 GB. The fancier templates and assets sit behind a Canva Pro subscription.
Pros and Cons
| Pros | Cons |
|---|---|
| Most visually polished output | Not designed for technical diagram types |
| Gentlest learning curve for non-technical users | Connector and routing logic is limited |
| Large template library | No support for UML, BPMN, or network diagrams |
| Well suited for presentations and social media | Premium templates are locked behind a paid plan |
Best For
Marketers, teachers, and anyone whose diagrams will end up in a deck, a report, or a social post, situations where looking good outranks being technically rigorous.
7. Creately - Best for Visual Project Management
Creately sits at the intersection of diagramming and project tracking. Its pitch is that a diagram should not just sit there as a picture, it should connect to the tasks and data your team is actually working on, which is exactly what draws workflow-minded teams to it.
Key Features
- Visual workspace: Mix diagrams, notes, tasks, and data on one shared canvas
- 50-plus diagram types: Flowcharts, org charts, UML, wireframes, SWOT analysis templates, and more
- Real-time collaboration: Multiple cursors with in-context threaded comments
- Database-linked shapes: Attach structured data records to individual visual elements
- Integrations: Works with Jira, Confluence, Slack, and Microsoft Teams
Free Tier
You are capped at 45 items on any one canvas. That is fine for a straightforward diagram but starts to pinch the moment your work grows more elaborate.
Pros and Cons
| Pros | Cons |
|---|---|
| Combines diagramming with project management | 45-item cap is limiting for complex diagrams |
| Clean and modern interface | Performance can lag on large files |
| Solid template library | Fewer integrations than Lucidchart or Miro |
| Data-linked shapes are a standout feature | Occasional syncing delays |
Best For
Small teams that want their diagrams to stay alive and wired into project workflows, rather than being exported once and forgotten.
8. PlantUML - Best for Code-Based UML
The idea behind PlantUML is that a diagram is really just another file to be treated like source code. You describe it with a compact text syntax, the engine draws it for you, and because the definition is plain text, you can commit it, diff it, and regenerate it the same way you handle the rest of your codebase.
Key Features
- Text-based syntax: Author diagrams in plain-text source files
- Comprehensive UML support: Covers sequence, class, activity, component, state, use case, and object diagrams
- Beyond UML: Handles Gantt charts, mind maps, entity-relationship diagrams, and wireframes as well
- IDE integration: Plugins available for VS Code, IntelliJ, Eclipse, and many others
- Version control friendly: Plain-text files integrate naturally with Git
Free Tier
The open-source build is free outright. If you would rather not install anything, a public rendering server will turn your text into diagrams on demand.
Pros and Cons
| Pros | Cons |
|---|---|
| Ideal for developer workflows involving Git and CI/CD | Requires learning PlantUML syntax |
| Highly reproducible output | Layout customization is limited |
| Free and open source | Java runtime is a prerequisite |
| Wide IDE plugin support | Output style is functional rather than decorative |
Best For
Developers and architects who like their diagrams checked into the repository next to the code, and who reach for a text editor before a mouse.
9. Mermaid.js - Best for Markdown-Native Diagrams
Mermaid.js lives wherever your writing already does. This JavaScript library reads a Markdown-flavored syntax and draws the diagram right inside the page, whether that page is a web doc, a GitHub README, or one of dozens of supported documentation platforms. There is no separate app to open, the diagram simply appears in context.
Key Features
- Markdown-like syntax: Approachable for anyone already comfortable with Markdown
- GitHub native: Diagrams render inline inside
.mdfiles on GitHub - Wide platform support: Works in Notion, GitLab, Docusaurus, Obsidian, and many other documentation tools
- Multiple diagram types: Flowcharts, sequence diagrams, Gantt charts, class diagrams, state diagrams, pie charts, and more
- No installation: Runs in the browser via a CDN link
Free Tier
It is open source and free end to end. When you want to draft or preview something quickly, the Mermaid Live Editor gives you a sandbox right in the browser.
Pros and Cons
| Pros | Cons |
|---|---|
| Renders natively in GitHub and GitLab | Styling options are limited |
| No installation required | Less expressive than PlantUML for complex UML work |
| Extremely lightweight | No graphical drag-and-drop interface |
| Purpose-built for documentation | The layout algorithm can produce unpredictable results |
Best For
Anyone documenting a project in Markdown who wants the diagram to show up inline instead of being maintained in a separate tool. README files, wikis, and engineering docs are its natural home. If you need to turn that output into shareable image files, our guide on how to convert Mermaid diagrams to images walks through it.
10. Google Drawings - Best for Simple Diagrams in Google Workspace
Tucked away inside Google's productivity suite, Google Drawings rarely gets the spotlight. It will never win on features, but it has one trick none of the others can match: it drops straight into Docs, Sheets, and Slides as a native part of the ecosystem you may already be living in all day.
Key Features
- Google Workspace integration: Embed diagrams straight into Docs and Slides
- Real-time collaboration: The same live editing experience found in Google Docs
- Simple interface: Minimal setup and a shallow learning curve for basic tasks
- Free with a Google account: No separate signup or subscription required
- Web-based: Runs in any modern browser
Free Tier
If you have a Google account, you already have it, at no cost and with no caps on how much you use it.
Pros and Cons
| Pros | Cons |
|---|---|
| Free with an existing Google account | Shape library is narrow |
| Seamless Google Workspace integration | No dedicated diagram standards like UML or BPMN |
| Real-time collaboration | Connector routing is basic |
| No installation required | Interface looks dated compared to modern alternatives |
Best For
People who live inside Google Workspace and just need a basic flowchart, org chart, or concept map dropped into a document, without the detour of opening a separate application.
Matching Tools to Use Cases
No single tool wins at everything, so the smarter question is which one wins at the thing you are doing right now. Use the pairings below as a shortcut from your task to a sensible default.
Flowcharts and Process Diagrams
When you are mapping a business process or a decision tree, Draw.io gives you the most room to work with, no document ceiling and a deep shape catalog. Prefer to skip the manual build entirely? Describe the flow to Figviz and let the AI draft it for you.
UML and Software Architecture
Developers who want their diagrams under version control tend to land on PlantUML or Mermaid.js. If you would rather drag shapes around, Lucidchart and Draw.io both handle UML well. We go deeper into the notation itself in our UML diagram types guide.
Mind Maps and Brainstorming
For a room full of people riffing together, Miro is the obvious call. Working alone, you can hand a short prompt to Figviz and get back a structured mind map almost immediately.
Mind Map Generator
Create detailed mind maps from any topic or text. AI-powered branching and organization for research, study, and project planning.
Network and Infrastructure Diagrams
If you need vendor icon sets, Draw.io ships the broadest free collection, with Cisco, AWS, Azure, and GCP libraries all included. Lucidchart matches that breadth, though you will bump into its three-document limit sooner.
Scientific and Research Diagrams
This is the corner Figviz was designed for, covering everything from ER diagrams to circuit diagrams and conceptual frameworks. For the wider picture, our scientific diagram guide for research papers is a good next read.
Quick Sketches and Wireframes
Nothing beats Excalidraw when you just need to get a rough idea on screen fast. The scrappy hand-drawn finish is a feature, not a flaw, it stops you from polishing a throwaway sketch into oblivion.
What to Consider When Evaluating Free Diagram Software
A free tier looks generous until a hidden limit catches you mid-project. Run through the checks below before you commit so nothing surprises you later.
1. Diagram Type Support
The first question is whether the tool even speaks your dialect. A flowchart builder is no use when you actually need entity-relationship modeling, so if UML matters to you, confirm the proper shapes and notation are present before you start.
2. Export Quality
A diagram you cannot export cleanly is half a diagram. Check the free plan for high-resolution output, since some products stamp a watermark on free exports or quietly cap the resolution.
3. Collaboration Features
If other people will be editing alongside you, real-time co-editing is non-negotiable. Miro, Lucidchart, and Excalidraw all do it natively, while text-driven tools such as PlantUML and Mermaid.js lean on version control to keep contributors in sync.
4. Integration Ecosystem
Picture where the finished diagram has to live. Inside Google Workspace, Google Drawings embeds with zero friction. For Markdown documentation, Mermaid.js renders right in the page. And if your team runs on Confluence, both Lucidchart and Draw.io offer proper plugins.
5. Learning Curve
Some tools you can use the second they load, Canva and Draw.io among them. Others, like PlantUML, ask you to pick up a syntax first. AI options such as Figviz cut that ramp-up to nearly zero, since the instruction is just plain language.
6. Data Privacy
The moment a diagram captures something sensitive, network topology, internal processes, system architecture, where it gets stored and processed starts to matter. Open-source choices like Draw.io and Excalidraw let you keep files local or self-host them, so the data never leaves your control.
Frequently Asked Questions
What is the best completely free diagram software?
Draw.io (Diagrams.net) leads the pack for genuinely free diagramming. You get unlimited documents, a broad shape library, offline use, and exports in several formats, with no paid tier ever required. Because it is open source, you can also self-host it and keep full ownership of your data.
Is there a free alternative to Microsoft Visio?
Draw.io (Diagrams.net) is the closest free stand-in for Visio. It opens .vsdx files, ships shape libraries of similar scope, and uses a drag-and-drop layout that Visio users will recognize at once. If your needs are lighter, Lucidchart's free tier also imports Visio files, just within its three-document cap.
Can I create UML diagrams for free?
Absolutely. PlantUML and Mermaid.js are both free and open source, generating UML straight from text syntax. If you want a visual editor instead, Draw.io offers one with no document limit, and Lucidchart handles UML on its free plan up to three documents.
Which free diagram tool is best for teams?
For group work, Miro is the standout free choice, with live co-editing, visible cursors, voting, and facilitation tools baked in. Technical teams often prefer Excalidraw, which spins up instant collaboration from a shared link with no accounts needed. Lucidchart and Creately also include team features on their free plans.
What is the easiest diagram software for beginners?
Among traditional tools, Canva is the gentlest entry point thanks to its huge template library and a drag-and-drop editor anyone can pick up. For an even shorter path, AI tools like Figviz remove the editor altogether: you write a description and get a finished diagram back, no design skills involved.
Are free diagram tools good enough for professional use?
They can be. Draw.io exports high-resolution PNG, SVG, and PDF files that hold up in business documentation, while PlantUML and Mermaid.js are everyday staples on professional engineering teams. Figviz, for its part, turns out publication-grade scientific figures within the free credit allowance.
Can I use free diagram software offline?
A few do work offline. Draw.io ships a free desktop app for Windows, macOS, and Linux that runs with no connection at all, Excalidraw supports offline use via its PWA install, and PlantUML executes locally once Java is in place. Most of the rest, including Lucidchart, Miro, and Canva, need you to be online.
What is the difference between a diagramming tool and a whiteboard tool?
It comes down to structure versus freedom. Diagramming tools such as Draw.io and Lucidchart center on precise shapes, clean connectors, and formal standards like UML and BPMN. Whiteboard tools like Miro and Excalidraw favor loose, open collaboration where diagramming is just one of many activities. Reach for a whiteboard early in the thinking, and a diagramming tool when it is time to document.
Final Thoughts
There is no universal winner here, only the tool that suits the job in front of you. Use these quick prompts to point yourself in the right direction:
- Want everything for free with nothing held back? Draw.io is the one to beat.
- Would rather type a description than build by hand? Hand it to Figviz and skip the layout work.
- Building with a team? Lean on Miro while you are still ideating, and Lucidchart once it needs to look formal.
- Documenting code as a developer? Mermaid.js slots into Markdown, while PlantUML covers the full UML range.
- Need something that looks good fast? Canva for polish, Excalidraw for an easygoing hand-drawn feel.
Not one of these tools asks for a credit card to do real work. Pick whichever lines up with your main task and get going, because in the end the diagram that wins is simply the one that makes your idea land, no matter what drew it.
Explore more diagramming resources: learn about UML diagram types, create ER diagrams for research, or discover how to make scientific diagrams for research papers.
Author
Categories
More Posts
Scientific Infographic Design: Complete Guide for Researchers and Scientists
Learn how to create compelling scientific infographics that communicate research clearly. Covers design fundamentals, data visualization, typography, color theory, and platform-specific best practices.
Applied Research vs Basic Research: Definitions, Differences, and Real Examples
Understand the distinction between applied and basic research: how they differ in goals, timelines, funding, and outcomes, with concrete examples across science, medicine, and education.
3 Minute Thesis Presentation: How to Win 3MT with One Slide (2026)
Everything you need to nail the 3 Minute Thesis competition: slide design principles, a battle-tested script structure, delivery tactics, and the most common pitfalls to sidestep.