Your file
It edits the .mmd file itself.
Mernyx vs VS Code for Mermaid: preview or editor
VS Code draws Mermaid in the Markdown preview — a picture inside a document. Mernyx is for the case where the diagram is the file, and you want to change it with the mouse.
Why Mernyx
What Mernyx does on the three rows where the two tools part ways.
Changing it on the canvas
Supported
Finder preview
Supported
When VS Code is the right choice
If you already write your documentation in VS Code, the built-in Mermaid preview is the shortest path.
A diagram inside a Markdown document is a picture in a document, and VS Code renders it well — no extension, no preview server, no second window. Mernyx is for the moment the picture stops being a picture and becomes the file: you want to move a node, and the source has to change with it. Many people keep both, and the question is not which one is better but which one you are holding.
Mechanism by mechanism
One row per feature. The left column is Mernyx; the right one is the tool this page is about.
| Feature | Mernyx | VS Code |
|---|---|---|
| Drawn natively | SupportedDrawn natively: every node is a real view, and the layout is computed on your Mac. | Partly supportedRendered with non-native technology. |
| Your file | SupportedIt edits the .mmd file itself. | Partly supportedThe diagram lives in a Mermaid code fence in a Markdown document. |
| Finder preview | SupportedSupported | Not supportedNot supported |
| Finder thumbnail | SupportedSupported | Not supportedNot supported |
| Changing it on the canvas | SupportedSupported | Not supportedNot supported |
| Working offline | SupportedCompiling, layout and export happen on your Mac, so it works the same with no network. | SupportedVS Code is a local app: the diagram draws the same with no network. |
| Export | SupportedPNG, SVG and PDF, no watermark, at whatever size you want. | Not supportedThe preview draws the diagram and copies its source. It does not export an image. |
| Nothing to install | SupportedOne app. No extension to install, no runtime to set up. | SupportedNeeds an extension installed. |
| Sharing | SupportedShare the file | SupportedShare the file |
| Icons | SupportedSupported | SupportedSupported |
| AI | SupportedBring your own key: you supply the endpoint and the key, completely free of restrictions. | Partly supportedVS Code ships no Mermaid AI of its own. |
| No account needed | SupportedNo account needed | SupportedNo account needed |
Questions
Does VS Code render Mermaid now?
Only from inside Markdown, or by installing a third-party extension.
So why a separate app?
Stronger visual editing, integration with macOS system features such as Quick Look, and native high-performance rendering.
Can I move a node in VS Code and have the Mermaid source change?
Not in the built-in preview — what it renders is a result, not an editable canvas. In Mernyx the canvas and the source are two views of one document: dragging a node rewrites the source, and editing the source redraws the canvas.
Try it free.
Download it, open a file you already have, and see whether the canvas earns its $19 when you need to change something.