Mermaid Viewer
Preview and render Mermaid diagrams from pasted code with export options.
Sometimes you only need to see whether Mermaid code renders correctly before merging a docs PR or sharing a snippet in chat. Utilitoo's Mermaid Viewer accepts pasted diagram code and displays the rendered output beside the source so you can verify syntax and layout at a glance.
Technical writers preview README diagrams, developers inspect Mermaid blocks copied from issue threads, and reviewers validate documentation changes without cloning a repo or running a local preview server. If something fails to render, the error message appears next to your code so you can fix it quickly.
When the diagram looks right, export SVG for embedding in static sites or PNG for email and slides. Copy the source back to your clipboard to paste into Notion, GitHub, or any Markdown-compatible platform.
Rendering runs entirely in your browser on Utilitoo. Your diagram text is not uploaded or stored. Free, instant, and privacy-first for anyone who needs a quick Mermaid preview without installing tools or extensions.
Live preview follows your site theme. Toggle light/dark mode from the header.
Diagram preview will appear here…
How to use
- Paste Mermaid diagram code into the source panel.
- Review the rendered preview on the right.
- Copy code or export SVG/PNG if you need to share the output.
Frequently Asked Questions
How do I view a Mermaid diagram online?▼
Paste your Mermaid code into Utilitoo's source panel. The viewer renders the diagram instantly in the preview pane next to your code.
Can I preview Mermaid from a GitHub README?▼
Yes. Copy the Mermaid fenced code block from your README and paste it into Utilitoo to confirm it renders before you publish.
What happens if my Mermaid syntax is invalid?▼
Utilitoo shows an error message in the preview area so you can locate and fix the problem in your source code.
Can I export a diagram from the Mermaid viewer?▼
Yes. Use Export SVG or Export PNG to download the rendered diagram after previewing it.
Is pasted Mermaid code stored anywhere?▼
No. Utilitoo renders diagrams locally in your browser. Your code is not transmitted to or saved on any server.
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