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Chartai vs Mermaid Chart

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. Chartai starts at $5, Mermaid Chart at $80. Both have a free tier.

ChartaiChat interface that turns a description into a Mermaid diagram, sold as credits where one credit is one diagram.Mermaid ChartTurns text, code, or prompts into flowcharts, sequence diagrams, and Gantt charts, from the Mermaid.js team.

Side by side

FactChartaiMermaid Chart
CategoryDiagramming & WhiteboardsDiagramming & Whiteboards
Pricing modelFreemiumFreemium
Starts at$5 month$80 year
Public APINoNo
PlatformsWebWeb, Vscode Ext
CompanyNeural Canvas Inc.Mermaid Chart
Launched—2022
Last verifiedSep 6, 2026Sep 1, 2026

What our research says

Chartai

The pricing is the clearest thing about it - one credit, one diagram, no conversion maths - and $5 for 25 diagrams is cheap for occasional use. Mermaid output means the diagrams are text you can keep and edit elsewhere. Against that, the app is a lightly reskinned chat client with ad-network tags on the page, and the vendor's country and support arrangements are barely documented.

Pros

  • One credit equals one diagram, with no hidden token conversion
  • Both subscription and one-time credit purchases available
  • Renders Mermaid, so output can be exported and edited as text
  • Starter tier is $5/month, among the cheapest in this category

Cons

  • The interface is a generic chat client shell with little diagram-specific tooling
  • The page carries ad-network tags, which is unusual for a paid product
  • No company address or country disclosed - only an Inc. name in the footer
  • No API, no collaboration features, and no version history at any tier

Mermaid Chart

Being built by the Mermaid.js maintainers themselves is the real edge here: diagrams-as-code that developers already write in markdown get a proper collaborative editor and AI-assisted generation on top, instead of a third party reverse-engineering the syntax. The free tier's five-diagram cap is tight, and the vendor's recent rebrand from mermaidchart.com to mermaid.ai makes some third-party pricing pages describing it look slightly out of date.

Pros

  • built and maintained by the original Mermaid.js open-source team
  • generates diagrams from plain text or AI prompts, or direct syntax editing
  • real-time multi-user collaboration
  • integrations with VS Code, Confluence, and similar developer tools

Cons

  • free plan is capped at five diagrams
  • recent domain move from mermaidchart.com to mermaid.ai has left some third-party listings referencing the old pricing page
  • per-user annual billing can add up for larger teams versus flat team pricing

Which one fits

Choose Chartai if you need

  • Students and occasional users who need a handful of diagrams a month
  • Anyone who wants Mermaid source they can paste into docs or a README
  • Quick flowcharts and sequence diagrams described in prose

Choose Mermaid Chart if you need

  • developers already writing Mermaid syntax who want a hosted editor
  • teams wanting diagrams generated from text or code with light AI assistance

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