Best for
Best for developers and technical writers who keep diagrams as text next to their code and documentation.
- Freelancers
- Small and mid-sized
- Enterprise
Whiteboards & Diagramming Comparison
Mermaid Chart vs. OmniGraffle
At a glance
At a glance
Best for
Best for individual designers and engineers on Apple hardware who need precise, scriptable diagrams rather than a shared workshop board.
Cataleo does not name a winner. Both statements come from the vendors themselves.
Full Comparison
| Criterion | Mermaid Chart | OmniGraffle |
|---|---|---|
| Starting price | lower value Free plan; from $10 / user / month Plus, billed annually. Premium is $20 per user and month, billed annually; Enterprise is priced on request. | From $59.99, one-time OmniGraffle 3 Standard for iPad and iPhone. Pro for iPad and iPhone is $119.99; on Mac, OmniGraffle 7 Standard is $149.99 and Pro $249.99. The annual subscription is $129.99 a year and covers Mac, iPhone and iPad. Upgrade discounts are offered. |
| Free trial | Free Basic plan with a capped number of diagrams, a diagram size limit and 15 AI credits | Free 14-day trial |
| Output | Flowcharts, sequence, Gantt, ER, class, state, C4, architecture, mind map and other Mermaid diagram types | Diagrams, flowcharts, mind maps, rapid prototypes and vector graphics |
| API | API access by request form, plus the official Mermaid MCP server | JavaScript automation on Mac, iPad and iPhone, plus AppleScript on Mac (Pro) |
| Hosting | Browser-based SaaS | Native apps for macOS 14 and iOS and iPadOS 16 or later |
| Made in | Not stated | United States (The Omni Group) |
| What it makes | Diagrams in the Mermaid syntax: flowchart, sequence, Gantt, ER, timeline, mind map, org chart, block, state, git graph, user journey, class, pie, quadrant, Sankey, C4, requirement and architecture diagrams, plus presentations built from them | Diagrams, flowcharts and mind maps, rapid prototypes and vector graphics, on canvases of fixed, flexible or infinite size |
| Templates and styling | Themes and looks, node borders, colours and text colour, styled edges, icons and images | Reusable stencils with instant search into Stenciltown, a free library of user-made stencils, plus templates that set units, grids and colours, and custom templates |
| Diagramming | A code editor where Mermaid text lays itself out, linked both ways to the canvas, a visual editor with node alignment and edge reattachment, and a drag-and-drop whiteboard with basic, process and technical shapes and hierarchical or adaptive layouts | Automatic layout through the Graphviz engine in circular, radial, hierarchical or force-directed arrangements, an outline view for flowcharts and mind maps, and layers per canvas; Pro adds shared layers, artboard layers, subgraphs and tables |
| Collaboration and facilitation | Comments on diagrams; on Premium several people edit the same diagram simultaneously, on Plus teammates can view and comment but not co-edit | No real-time co-editing: Omni recommends syncing documents through iCloud Drive, and its legacy OmniPresence sync, which lets several people share one Omni Sync Server account, was designed for documents that are not being used collaboratively; stencils are shared through Stenciltown |
| Permissions and guests | Diagrams are private, view-by-link or edit-by-link, and link viewers need no account; teams in an organisation restrict projects to their members, unlimited free viewer seats on Premium, SSO on Enterprise | Set per document rather than per person: a document can be made read-only, for example stencils shared with a design team, and objects, layers and guides can be locked against edits |
| Export and sharing | Export as PNG or SVG or as an MMD code file, an SVG link for embedding in wikis, and plugins for Confluence, Jira, Google Docs, Word and PowerPoint | Export to PNG, PDF, JPG, GIF, BMP and TIFF, Visio import (.vsd, .vsdx, .vdx, .vst, .vtx, .vss, .vsx); Pro adds Visio and SVG export, HTML image maps and an artboard presentation mode |
| AI features | Yes, Mermaid AI generates diagrams from a description, an uploaded document or a pasted transcript, suggests a fitting diagram type and edits through a prompt bar in the code panel or canvas; metered in AI credits by plan | None in OmniGraffle 7 for Mac or OmniGraffle 3 for iPad and iPhone; The Omni Group's 2026 roadmap plans Omni Automation access to Apple Intelligence's on-device models for OmniGraffle 8 |
| MCP-ready | stated Yes | No |
| Deployment | more entries Cloud (SaaS), Browser-based | On-premise |
| Support | Community forum | more entries Email helpdesk, Phone, Community forum |
| Onboarding | Documentation and knowledge base | more entries Documentation and knowledge base, Video tutorials |
| Company size | Freelancers, Small and mid-sized, Enterprise | Not stated |
| Integrations | Visual Studio Code, JetBrains IDEs, Cursor, Windsurf, Claude Code, GitHub, GitHub Copilot, ChatGPT, Confluence, Jira, Google Docs, Microsoft Word, Microsoft PowerPoint | Not stated |
Add a tool
Adds a column to the table, from the tools in this category.
Row where the values differ The small markers point at the lower number, the longer list or the stated feature. They describe the data, they are not a verdict.
The short version
Key Differences
- Starting price Mermaid Chart Free plan; from $10 / user / month OmniGraffle From $59.99, one-time
- Free trial Mermaid Chart Free Basic plan with a capped number of diagrams, a diagram size limit and 15 AI credits OmniGraffle Free 14-day trial
- Deployment Mermaid Chart Cloud (SaaS), Browser-based OmniGraffle On-premise
- Hosting Mermaid Chart Browser-based SaaS OmniGraffle Native apps for macOS 14 and iOS and iPadOS 16 or later
- Support Mermaid Chart Community forum OmniGraffle Email helpdesk, Phone, Community forum
Every line is one datapoint from the table above, picked automatically. Nothing here is written text.
The trade-offs
Strengths and Limitations
Mermaid Chart
Strengths
- Same syntax as the open-source Mermaid.js already rendered in many wikis and repositories
- Code, visual editor and whiteboard work on the same diagram
- Official MCP server, usable with a free account
- Plugins for VS Code, JetBrains IDEs, Confluence, Jira, Google Docs and Microsoft Office
Limitations
- The free plan stops at a handful of diagrams with a size limit
- Simultaneous co-editing needs Premium; Plus is view and comment only for teammates
- API access is by request rather than self-service
OmniGraffle
Strengths
- Graphviz-based automatic layout in four arrangements
- Imports every common Visio file type
- Stencils, projects and scripts carry across Mac, iPad and iPhone
- One-time licence available alongside the subscription
Limitations
- Apple platforms only, no browser or Windows version
- Visio and SVG export, presentation mode and scripting need Pro
- A licence bought for Mac does not cover iPad and iPhone, and the reverse
Plans
Pricing
Mermaid Chart
- Basic $0 A capped number of diagrams, limited diagram size, 15 AI credits, 1 team and project.
- Plus $10 Per user and month, billed annually. Unlimited diagrams with no size limit, 300 AI credits per year.
- Premium $20 Per user and month, billed annually. Adds 2,000 AI credits per year, unlimited free viewer seats, unlimited teams and projects and simultaneous co-editing.
- Enterprise Custom Billed annually. Adds SSO, custom contract and invoicing, IP management and a dedicated customer success manager.
OmniGraffle
- iPad and iPhone Standard $59.99 One-time licence for OmniGraffle 3.
- iPad and iPhone Pro $119.99 One-time licence for OmniGraffle 3.
- Subscription $129.99 Per year, auto-renews until cancelled. Covers Mac, iPhone and iPad.
- Mac Standard $149.99 One-time licence for OmniGraffle 7.
- Mac Pro $249.99 One-time licence for OmniGraffle 7. Adds shared and artboard layers, Visio and SVG export, presentation mode and scripting.
What users say
Review Scores · opens after launch
Mermaid Chart
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Nothing has been published here yet, and no score is shown. How a review is checked before it appears is described below.
OmniGraffle
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Nothing has been published here yet, and no score is shown. How a review is checked before it appears is described below.
How we check reviews
Reviews are not published yet. The form on a tool's page works and reaches us, but nothing from it appears on this site, so no score here is based on a review. The rules below are the ones that will apply once reviews go live.
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What we cannot do is verify a purchase. There is no shop here and no account, so whether the author really used the tool rests on what they tell us, plus the plausibility of what they write. We say so rather than implying a check that does not exist.
A vendor cannot have a review removed, cannot buy one, and cannot have one changed. Paid placement and a paid listing have no effect on which reviews appear or on any score.
Where this comes from
Where this comes from
Mermaid Chart https://mermaid.ai · checked against the official source on 2026-10-18
OmniGraffle https://www.omnigroup.com/omnigraffle · checked against the official source on 2026-10-18
This table lists factual criteria taken from information the vendors publish themselves. For how we put it together, see the methodology.