Mermaid vs Swimlanes.io (2026): which should you pick?
As of Nov 13, 2026, Swimlanes.io grades higher than Mermaid: 2.8 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 platforms. Swimlanes.io grades higher on value for money and the free plan. They get the same grade on ease of use.
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
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 Swimlanes.io if
- Fits if you write a sequence diagram a week and want it from text
- Works for explaining an API call or a login flow to someone with a link
Look elsewhere if
- Skip it if you want a freeform canvas or sticky notes: it draws sequence diagrams only
- Watch out: without an account the web address changes on every edit, so an old link shows the old diagram
- Not for you if your company needs a named vendor and published terms, because the site gives neither
- Too light for teams: no real-time collaboration is listed
How we grade them
| 2.4GPAMermaidFair | 2.8GPASwimlanes.ioGood | |
|---|---|---|
| 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. | AFree, with no paid plan listed. It is a web app anyone can open and use, which beats every price in the category. |
| 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. | AFree outright: no plan, cap or trial on the page. An account is optional and only collects your diagrams. |
| 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, with flow structures, Markdown, sharing and export. That is a smaller job than a whiteboard, with no freeform canvas. |
| 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 write the diagram in a text syntax, so there is a short learning curve. |
| 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. | CWeb only. Sign-in goes through Google or GitHub, and no apps or integrations are listed. |
| Best for | diagrams you write as text, then tidy by hand | quick sequence diagrams in the browser |
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 Swimlanes.io. 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. Swimlanes.io has no paid plan and scores 2.0.
Mermaid scores higher, and starts $10 a month higher: the question is whether the extra is worth that to you. Of the other whiteboard and mind map tools on the chart, 11 score higher than Mermaid for less, and none scores higher than Swimlanes.io 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
- Mermaid also covers presentations.
- Swimlanes.io also covers Markdown and file sharing.
At a glance
| Mermaid | Swimlanes.io | |
|---|---|---|
| Pricing | Free plan | Free |
| Starts at | $10 per user / month, billed annually ($120 a year) | Free |
| 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. | None |
| Free trial | Free trial of Plus or Premium; the vendor does not state how long it lasts | None listed |
| Web | ||
| Made by | Mermaid Chart | Swimlanes.io |
| Price read from | mermaid.ai | swimlanes.io |
| 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.
Swimlanes.io
- Without an account, the diagram lives in the URL and the URL changes whenever the diagram is edited.
- It draws sequence diagrams only, with no freeform canvas.
- The site does not name the company behind it or publish terms or a pricing page that we could read.
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.
Swimlanes.io
- Live text editing
- Edit the text on the left and the sequence diagram on the right updates in real time.
- Markdown in messages and notes
- Messages and notes accept italic, bold, strike-through and inline code, plus lists, links, code blocks and Font Awesome icons.
- Flow structures
- The syntax covers conditional sections with if and else, groups, dividers, delays, automatic numbering and actor reordering.
- Sharing and export
- Diagrams can be shared as a link, short URL, image link or embed, or downloaded as an image or PDF.
- Optional account
- Signing in with Google or GitHub collects a person's diagrams in one place; without it the URL carries the diagram.
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.
Swimlanes.io
Free$0
The site describes itself as a free web app; no paid plan is listed.
Common questions
Which is cheaper, Mermaid or Swimlanes.io?
As of Nov 13, 2026, Swimlanes.io is cheaper to start with: it is free, against $10 a month for each person for Mermaid. Mermaid starts at $10 per user / month, billed annually ($120 a year), and Swimlanes.io is free.
Which has a free plan, Mermaid or Swimlanes.io?
As of Nov 13, 2026, both Mermaid and Swimlanes.io 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.