Mermaid

Mermaid is a text-driven diagramming and charting tool for developers, technical writers, analysts, educators, and teams that want visualizations to live alongside code or documents. It also serves visual thinkers through AI-assisted creation and collaborative editing, but users who prefer unrestricted canvas work should weigh its text-first workflow and Basic limits carefully.

Overview

Mermaid turns Markdown-inspired definitions into flowcharts, sequence diagrams, class diagrams, state diagrams, Gantt charts, timelines, mind maps, Git graphs, use case diagrams, and event modeling diagrams. That breadth covers software architecture, planning, process explanation, and documentation in one format. The defining trade-off is interaction: structured text is efficient for repeatable, reviewable diagrams, while people who primarily arrange shapes visually may find a canvas-oriented product more natural.

Mermaid Chart extends the format with real-time co-editing, click-based diagram adjustments, and live links that viewers can open without an account. AI can create a starting diagram from an idea, uploaded document, or transcript and support further refinement in a context-aware conversation. Those additions make Mermaid viable for mixed technical and nontechnical teams, although sustained AI use and larger diagram collections require a paid tier.

Key features

Creation and collaboration

The text definition is the central asset: it can be reviewed, edited, and maintained as part of a technical workflow rather than treated as a standalone graphic. Export to PNG, SVG, or Markdown supports presentation, documentation, and source-oriented use, while .mmd import helps bring existing Mermaid definitions into the workflow. Version history provides a way to revisit changes.

Mermaid supports integrations with VS Code, JetBrains IDEs, Cursor, Windsurf, Claude Code, ChatGPT, Confluence, Jira, Google Docs, Microsoft Word, and PowerPoint. Community integrations include GitHub, GitLab, Notion, Obsidian, Joplin, and Azure DevOps. This range is particularly useful when diagrams must appear in both developer tools and business documentation, though the experience will vary by integration.

Deployment and security

Use the Live Editor, install Mermaid as an npm dependency, load it from a CDN, or deploy it through the API. That flexibility suits documentation pipelines and self-managed environments as well as browser editing. Mermaid v12 targets ES2024; its documentation aims to support Safari 17.4 or later, and the npm package requires Node.js 22.12.0 or later. Those requirements can rule it out for older browser or runtime environments.

Rendering defaults to strict security, encoding HTML tags in text and disabling click functionality. Sandbox mode renders in a sandboxed iframe. The project accepts vulnerability reports by email and aims to respond within three working days. Mermaid Chart enterprise controls include SSO/SAML, SOC 2 compliance, encryption at rest, centralized seat management, and domain lockdown.

Pricing

Mermaid is open source and free to use, with a Basic tier at free. Basic allows up to six diagrams, a diagram-size limit of 60, 15 AI credits, and one team and project creation, with limited AI. It is suitable for occasional diagrams or evaluation, not a large shared workspace.

Plus costs $10 a month, billed annually. It removes diagram-count and size limits and supplies 300 AI credits per year. This is the sensible tier for an individual or small team producing diagrams regularly, provided unlimited viewer access and multiple projects are unnecessary.

Premium costs $20 a month, billed annually. It keeps unlimited diagrams and limitless size, raises AI allocation to 2,000 credits per year, and adds unlimited viewer seats, teams, and projects. Choose it when collaboration scale, rather than just authoring volume, is the constraint.

Enterprise uses custom pricing, billed annually. It adds unlimited AI credits, SSO, custom contracts and invoicing, IP management, and a dedicated Customer Success Manager. Organizations needing those controls should request a quote; smaller users gain little from this tier.

A free trial is offered, but the paid plans shown use annual billing, so confirm renewal and budget implications before committing.

Platforms

Mermaid is available through web, API, extension, Linux, macOS, Windows, and self-hosted deployments. The broad delivery choices support both browser users and teams embedding diagrams in software or infrastructure.

Who it's for

Mermaid is a strong fit for developers, data engineers, analysts, educators, consultants, technical writers, project managers, and teams that need diagrams synchronized with documentation or code. It is less suitable for users who want a purely visual, shape-first editor or who cannot meet the modern browser and Node.js requirements.

Pros and cons

• Pros: Broad diagram coverage from one text format; AI generation from ideas, documents, or transcripts; real-time co-editing and login-free live links; many editor, documentation, and collaboration integrations; flexible browser, package, CDN, API, and self-hosted deployment.
• Cons: Basic limits users to six diagrams, size 60, 15 AI credits, and one team/project; annual billing applies to Plus, Premium, and Enterprise; ES2024, Safari 17.4+, and Node.js 22.12.0+ requirements may exclude older environments; text-first authoring is not ideal for canvas-focused users.

Alternatives

draw.io is the better choice for a free, open-source, shape-oriented tool with no sign-up requirement across web, desktop, and mobile platforms.

EdrawMax suits users seeking a freemium visual application with mobile and desktop coverage, a free tier, and AI tokens.

Sparx Enterprise Architect is aimed at UML modeling and multi-user projects.

Structurizr fits teams prepared for server-based licensing charged per installation and unique-user range.

Creately is an option for free collaborative canvases with unlimited collaborators and canvases, subject to item limits.

Microsoft Visio is preferable when a paid Microsoft ecosystem product and OneDrive-backed plan are the priority.

PlantUML is a free, open-source alternative for text-defined diagrams without a free trial.

Archi is a free open-source desktop option for Linux, macOS, and Windows.

For broader comparisons, see Diagram Software and Diagramming Software.

Verdict

Choose Mermaid if you want maintainable, text-based diagrams that can move between code, documentation, AI assistance, and collaborative sharing. Its open-source foundation and deployment flexibility are compelling, but the Basic caps, annual paid terms, and modern runtime requirements make another tool a better fit for unrestricted visual editing, legacy environments, or occasional users who need more than six diagrams.