diagram.ch
diagram.ch: A free web tool for turning text into Mermaid diagrams and downloadable visuals. Ranked #27 of 32 in AI Diagram Generators by our editors (6.7/10); pricing: Free plan; best for simple free Mermaid diagram generation.
At a glance
- Editor score6.7 / 10
- PricingFree plan
- Best forSimple free Mermaid diagram generation
- Free planYes
- Paid fromFree
- Mermaid supportYes
- Facts checked20 Sep 2026
Where it wins
- Generates flowcharts, mind maps, sequences, and architecture diagrams
- Provides editable Mermaid source with .mmd download support
- Exports diagrams as SVG or PNG files
Where it doesn't
- Browser-based access only
- Free use includes a lightweight rate limit
- Does not include collaboration or integrations
Our verdict on diagram.ch
diagram.ch turns plain-language descriptions of processes, systems, workflows, and ideas into visual diagrams in a web browser. It is aimed at people who want to move from a written concept to a structured diagram without manually writing Mermaid syntax. Supported outputs include flowcharts, process diagrams, mind maps, sequence diagrams, and software architecture diagrams. The service does not require an account, which keeps the initial setup focused on describing the diagram rather than configuring a workspace.
Its standout feature is the connection between natural-language input and Mermaid source. Users can edit the description, regenerate the diagram, view the generated code, copy the Mermaid source, or download it as an .mmd file. That makes diagram.ch useful for technical documentation and workflows where the underlying text-based diagram definition matters, not just the rendered image. SVG and PNG export add options for sharing diagrams in documents, presentations, or other visual materials. The product is web-based, so diagram creation happens through a browser rather than a desktop or mobile application.
The service is free and includes several diagram generations, with a lightweight rate limit. That suits occasional diagram creation, early documentation, and users who want a straightforward Mermaid generator without a paid plan structure. It is less suitable for teams seeking shared editing, collaboration features, or integrations with other tools. Users who need those capabilities should consider a product built around a broader collaborative ecosystem. diagram.ch is the better fit when the priority is quick text-to-diagram generation, Mermaid control, and SVG or PNG export from a browser.
Your product? Our editors can test diagram.ch in depth and publish a review, labelled as paid · from $149/mo →
diagram.ch pricing
diagram.ch fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| AI diagram limit | Not verified |
| Mermaid support | Yes |
| Real-time collaboration | Not verified |
| Diagram import | Not verified |
| Platform | Web |
| Export formats | SVG, PNG, Mermaid source (.mmd) |
| Deployment | Cloud |
| Platforms | Web |
| Built for | Solo, Small business (editorial estimate) |
| Pricing | Free plan |
| Website | diagram.ch |
| Facts checked | 20 Sep 2026 |
Alternatives to diagram.ch
- OpenFlowKitA flexible free diagramming workspace for technical teams that prefer editable, portable outputs.9.4
- EraserA broad diagram workspace combining AI, diagram-as-code, collaboration, and integrations.9.3
- ArchwayA broad architecture diagram generator with AI input, collaboration, APIs, and self-hosting.9.2
See all diagram.ch alternatives →
Used diagram.ch? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used diagram.ch for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
diagram.ch is listed in our AI Diagram Generators directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/diagram-ch/"><img src="https://www.itechguides.com/best/badge/diagram-ch.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update