Mermaid vs WebSequenceDiagrams (2026): which should you pick?
As of Nov 13, 2026, Mermaid and WebSequenceDiagrams share a 2.4 GPA, both have a free plan and their prices can't be set side by side, so the choice depends on whether you care more about features, where Mermaid grades higher, or the free plan, where WebSequenceDiagrams does.
Checked Oct 6, 2026 and Nov 13, 2026 · graded Oct 10, 2026 and Nov 13, 2026 by ToolGPA
They get the same grade on value for money, ease of use and 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
WebSequenceDiagrams
Text-to-diagram sequence diagram maker with its own layout engine
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 WebSequenceDiagrams if
- Fits if you write sequence diagrams from text inside VS Code
- Works for a team of five or more that needs one block of Pro accounts
Look elsewhere if
- Skip it if you want freeform whiteboarding: it draws sequence diagrams only
- Tight if you stay free: wider diagrams and PDF or SVG export are Pro
- Pricey if you pay monthly: $15 against $10 billed annually
- Watch out: WSD Team is a block of 10 accounts at $699 a year, and Enterprise Server is $5,999 plus 20% yearly
How we grade them
| 2.4GPAMermaidFair | 2.4GPAWebSequenceDiagramsFair | |
|---|---|---|
| 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. | CWSD Pro is $10 a month billed annually, $15 monthly, against $8.25 in the middle for whiteboard tools. WSD Team is $699 a year for a block of 10. |
| 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. | BWSD Basic is free and lets you save your work and see revision history. The edge is paid: wider diagrams, PDF and SVG export and no branding. |
| 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. | CDoes sequence diagrams fully, plus HAR file analysis and a self-hosted edition. A smaller job than a whiteboard, and branding stays on until you pay. |
| 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. | CNo store rating on record. You learn a text syntax before the first diagram. |
| 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, with a VS Code extension and AI access via Claude and GitHub Copilot. No phone app. |
| Best for | diagrams you write as text, then tidy by hand | sequence diagrams written as text |
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 WebSequenceDiagrams. 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. WebSequenceDiagrams starts at $10 a month and scores 2.3.
Mermaid scores higher for the same starting price. Of the other whiteboard and mind map tools on the chart, 11 score higher than Mermaid for less, and 22 score higher than WebSequenceDiagrams 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
- WebSequenceDiagrams is self-hostable, according to its own site.
- Mermaid also covers presentations.
At a glance
| Mermaid | WebSequenceDiagrams | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | $10 per user / month, billed annually ($120 a year) | $10 per month, billed annually ($15 billed monthly) |
| 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. | WSD Basic: save your work, wider diagrams, revision history and PDF and SVG export. |
| Free trial | Free trial of Plus or Premium; the vendor does not state how long it lasts | None listed |
| Web | ||
| Made by | Mermaid Chart | Hanov Solutions Inc. |
| Price read from | mermaid.ai | websequencediagrams.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.
WebSequenceDiagrams
- It makes sequence diagrams only; it is not a freeform whiteboard.
- Branding is removed only on paid plans.
- The Team plan is sold as a block of 10 accounts, so it suits five or more users.
- Enterprise Server is quoted as a site license with 20% yearly maintenance and is sold through sales.
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.
WebSequenceDiagrams
- Text-based diagrams
- Diagrams are written as text and the engine lays out actors and messages without manual line routing.
- VS Code extension
- An official extension offers live side-by-side preview, syntax highlighting and snippets inside the editor.
- AI through MCP
- Claude, GitHub Copilot or other MCP-compatible assistants can generate diagram syntax that the engine then lays out.
- HAR file analysis
- HTTP Archive files can be converted into sequence diagrams that map cross-origin requests and API calls.
- Self-hosted edition
- The Enterprise Server edition runs on a company's own infrastructure so diagrams stay on the internal network.
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.
WebSequenceDiagrams
WSD Basic$0
Save your work, wider diagrams, revision history and high quality PDF and SVG export.
WSD Pro$10
per month, billed annually ($120 a year; $15 billed monthly)
Removes WSD branding; adds auto-save, parallel flows, auto-numbering and multipage PDF export.
WSD Team$699
per year for a block of 10 Pro accounts
All Pro features for 10 users, with centralized billing and priority email support.
Enterprise Server Edition$5,999
site license, plus 20% annual maintenance
Hosted on your own infrastructure for air-gapped use, with unlimited internal users; sold through sales.
Ways to pay less
Mermaid
No public discounts listed.
WebSequenceDiagrams
- Annual discount
Save 33% with annual billing
WSD Pro is $10 a month billed as $120 a year, against $15 a month on monthly billing; the pricing toggle labels the annual option as 33% off.
Common questions
Which is cheaper, Mermaid or WebSequenceDiagrams?
As of Nov 13, 2026, Mermaid starts at $10 per user / month, billed annually ($120 a year), and WebSequenceDiagrams starts at $10 per month, billed annually ($15 billed monthly). 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 WebSequenceDiagrams?
As of Nov 13, 2026, both Mermaid and WebSequenceDiagrams 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.