Mermaid vs Structurizr (2026): which should you pick?
As of Nov 13, 2026, Structurizr grades higher than Mermaid: 2.6 against 2.4 out of 4.0.
Checked Oct 6, 2026 and Nov 13, 2026 · graded Oct 10, 2026 and Nov 13, 2026 by ToolGPA
Mermaid grades higher on features and ease of use. Structurizr grades higher on value for money and the free plan. They get the same grade on platforms.
Price, platforms and features side by side. The table says where each price was read and when.
Mermaid
Text-based diagramming platform with AI and a visual editor
Structurizr
Open-source models-as-code tool for C4 architecture diagrams
Which one is for you
Pick Mermaid if
- Fits if you already write Mermaid syntax in your docs or Markdown
- Works for diagrams you want versioned and reviewed as text, like code
Look elsewhere if
- Skip it if you want to pay by the month, since paid plans are billed annually only
- Tight if you're staying free, with 3 diagrams on the plan card, a size limit and 15 AI credits
- Pricey if you lean on the AI, with 300 credits a year on Plus and 2,000 on Premium at $20
- Watch out: one page gives the free plan 3 diagrams on the card and 6 in the table, and the trial length isn't stated
- Not for you if you want a desktop or phone app, or free viewer seats below Premium
Pick Structurizr if
- Fits if you're a developer who keeps diagrams as code in version control
- Works for organisations that must host architecture diagrams themselves
Look elsewhere if
- Skip it if you want to drag shapes around, as it's code first
- Not for you if you don't want to learn its text language and command line
- Pricey if you want the prebuilt server: £300 a month for up to 20 users, £600 for up to 50
- Watch out: licenses are bought by contacting the vendor and are non-refundable, with prices in pounds
How we grade them
| 2.4GPAMermaidFair | 2.6GPAStructurizrGood | |
|---|---|---|
| Value for money | CPlus is $10 a user a month against a category middle of $8.33, and it's billed annually only, so you hand over $120 up front with no monthly option. That buys 300 AI credits for the whole year, and free viewer seats wait for Premium at $20. | AThe playground, local viewer and command-line export are free to download and use. Only the prebuilt server costs, at £300 a month for up to 20 users. |
| Free plan and trial | CBasic is free and includes co-editing and external sharing, but the caps arrive fast: 3 diagrams on the plan card, up to 6 in the comparison table on the same page, a limited diagram size and 15 AI credits. The trial of the paid plans has no stated length. | BOpen-source tools with no cap, but the prebuilt server needs a paid license, and building the open-core server yourself is up to you. A 14-day trial license is on request. |
| Features | BThe diagramming job, covered: flowcharts, sequence and ER diagrams, Gantt charts and mind maps written in Mermaid syntax and laid out for you, AI drafts from a document or transcript, a visual editor that rewrites the code as you drag, plus slides and live co-editing. | CModels as code, interactive diagrams, export to other formats and AI support. It does the C4 job completely, but it's a smaller job than a general whiteboard. |
| Ease of use | CNo rating on record. This is a tool you learn: Mermaid syntax has its own grammar per diagram type, and the AI drafts and click-and-drag editor soften that rather than remove it. Easier if you already write Mermaid in your docs, a curve if you don't. | DYou write a text language, use a command line and, for the server, host it yourself with Docker. |
| Platforms and integrations | BWeb only, with no desktop or phone app. It has plugins for VS Code, JetBrains IDEs, Cursor, Confluence, Jira, Google Docs, Word and PowerPoint, plus an MCP server so Claude or Cursor can generate diagrams. | BWeb playground plus a local viewer, command-line exporter and server, with PlantUML, Mermaid, S3 and Azure storage connections. |
| Best for | diagrams you write as text, then tidy by hand | C4 architecture diagrams written as code |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: Mermaid and Structurizr. How we grade
Price against what you get
Mermaid starts at $10 a month for each person and scores 2.7 out of 4 on features, ease of use and platforms. Structurizr starts at about $401.97 a month and scores 2.0.
Mermaid scores higher and starts $391.97 a month lower. Of the other whiteboard and mind map tools on the chart, 11 score higher than Mermaid for less, and 65 score higher than Structurizr for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Structurizr is open source and self-hostable, according to its own site.
- Mermaid also covers presentations.
At a glance
| Mermaid | Structurizr | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | $10 per user / month, billed annually ($120 a year) | £300 per month for up to 20 unique users, per server installation |
| Free plan | Basic plan: 3 diagrams (the comparison table on the same page says up to 6) with a limited diagram size, 15 AI credits, one team and project, and co-editing and external sharing. | Open-source tools: the browser playground, local viewer, CLI export and a self-built open-core server. |
| Free trial | Free trial of Plus or Premium; the vendor does not state how long it lasts | 14-day trial license on request that unlocks all features |
| Web | ||
| Made by | Mermaid Chart | Structurizr Limited |
| Price read from | mermaid.ai | docs.structurizr.com |
| Checked | Oct 6, 2026 | Nov 13, 2026 |
Worth knowing
Mermaid
- The free Basic plan is listed as 3 diagrams on its plan card and up to 6 in the comparison table, with a limited diagram size and 15 AI credits.
- Paid plans are billed annually only; the vendor's FAQ says monthly plans are not available.
- AI credits are capped at 300 a year on Plus and 2,000 a year on Premium; only Enterprise is listed as unlimited.
- Free viewer seats start at Premium, and SSO, invoicing and a customer success manager are limited to Enterprise.
Structurizr
- Using the server through the vendor's prebuilt binaries needs a paid license; building it yourself is open core.
- Prices are published in pounds sterling and are charged by unique users per server installation.
- Licenses are bought by contacting the vendor, with payment by bank transfer or PayPal invoice, and are non-refundable.
- It is a code-driven diagramming tool, not a freeform whiteboard.
Key features
Mermaid
- Diagrams from Mermaid code
- Diagrams are written in Mermaid syntax and laid out automatically. Clicking a node jumps to its code and clicking the code finds its shape, so the two stay in step.
- Mermaid AI
- A description, an uploaded document or a pasted transcript becomes a first-draft diagram, and the AI suggests a fitting diagram type. Use is metered in credits below Enterprise.
- Visual Editor
- Nodes, edges, labels, colors and shapes can be changed by clicking and dragging while the code rewrites itself, with node alignment and movable edges for tidying a layout.
- Live co-editing and share links
- Teammates can co-edit a diagram at the same time, and a share link lets other people view it without logging in. Free viewer seats are part of Premium and Enterprise.
- Plugins and MCP server
- Plugins cover VS Code, JetBrains IDEs, Cursor, Windsurf, Confluence, Jira, Google Docs, Word and PowerPoint. An MCP server lets Claude, VS Code and Cursor generate diagrams.
- Presentations
- Existing diagrams become slides written in Markdown. A deck updates when its diagrams change and can be shared through a public link for viewing and comments.
Structurizr
- Models as code
- Write the Structurizr DSL once and generate system context, container, component, dynamic and deployment diagrams from it.
- Interactive diagrams
- Diagrams can be zoomed, animated and embedded, and include an automatically generated key.
- Several ways to run it
- Use the browser playground, view diagrams locally, or run the self-hosted server as a Docker image or Java .war file.
- Export to other formats
- A CLI tool exports views to PlantUML, Mermaid or a static HTML site.
- AI and MCP support
- A free, open-source MCP server parses and validates DSL, exports diagrams and manages workspaces on a Structurizr server.
- Manual layout
- Diagrams use manual layout that can be adjusted in the local viewer, rather than auto-layout only.
Plans
Mermaid
Basic$0
3 diagrams with a limited diagram size, 15 AI credits, and one team and project. Co-editing and external sharing are included.
Plus$10
per user / month, billed annually ($120 a year)
Unlimited diagrams with no size limit and 300 AI credits per year, for individuals who diagram often.
Premium$20
per user / month, billed annually ($240 a year)
Everything in Plus, plus 2,000 AI credits per year, unlimited free viewer seats, and unlimited teams and projects.
EnterpriseCustom
Everything in Premium, plus SSO, custom contracts and invoicing, IP management, user consolidation and a dedicated customer success manager.
Structurizr
Open source$0
Playground, local, export CLI and the open-core server you build yourself; you host it.
Server license, 1-20 users£300
per month, per server installation
Prebuilt server binaries with enterprise features, priced by unique users in a year; sold by quote.
Server license, 21-50 users£600
per month, per server installation
The same prebuilt server; 51-100 users is £900 and 101-250 is £1,200 a month.
Server license, 1001+ users£2,400
per month, per server installation
Largest published tier; 251-500 users is £1,500 and 501-1000 is £1,800 a month.
Common questions
Which is cheaper, Mermaid or Structurizr?
As of Nov 13, 2026, Mermaid starts at $10 per user / month, billed annually ($120 a year), and Structurizr starts at £300 per month for up to 20 unique users, per server installation. One is priced for each person and the other is not, so which costs less depends on how many of you use it.
Which has a free plan, Mermaid or Structurizr?
As of Nov 13, 2026, both Mermaid and Structurizr have a free plan.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.