What each family supports
Mernyx renders 34 diagram families, and what it does with them is not the same on all of them. This is the whole list — what the canvas lets you do, what the source editor does, and a verdict on the canvas side — so you can check it before you buy rather than after.
The 34 families
One row per family, in the order Mernyx lists them. The first four columns are the canvas — what the Pro licence unlocks. The next three are the source editor — what the free build already does. The last column sums the canvas side up.
| Family | On the canvas | In the source | Verdict | |||||
|---|---|---|---|---|---|---|---|---|
| Structure | Style | Rename | Numbers | Highlighting | Formatting | Focus sync | ||
| Flowchart | can | can | can | cannot | can | can | can | Full editing |
| Sequence diagram | can | cannot | can | cannot | can | can | can | Partial |
| Class diagram | can | can | can | cannot | can | can | can | Full editing |
| State diagram | can | can | can | cannot | can | can | can | Full editing |
| ER diagram | can | cannot | can | cannot | can | can | can | Partial |
| Mindmap | can | cannot | can | cannot | can | can | can | Partial |
| Architecture diagram | can | cannot | can | cannot | can | can | can | Partial |
| Requirement diagram | can | can | can | cannot | can | can | can | Full editing |
| Block diagram | can | can | can | cannot | can | can | can | Full editing |
| Swimlane diagram | can | can | can | cannot | can | can | can | Full editing |
| Agent flow diagram | can | cannot | can | cannot | can | can | can | Partial |
| Use case diagram | can | cannot | can | cannot | can | can | can | Partial |
| Pie chart | cannot | cannot | can | can | can | can | can | Partial |
| Gantt chart | cannot | cannot | can | cannot | can | can | can | Partial |
| Quadrant chart | cannot | cannot | can | cannot | can | can | can | Partial |
| Radar chart | cannot | cannot | can | cannot | can | can | can | Partial |
| Treemap | cannot | partly | can | can | can | can | can | Partial |
| Kanban diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| Packet diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| Info diagram | cannot | cannot | cannot | cannot | can | cannot | cannot | Render only |
| Timeline | cannot | cannot | cannot | cannot | can | can | cannot | Render only |
| Sankey diagram | cannot | cannot | cannot | can | can | can | cannot | Partial |
| User journey | cannot | cannot | can | cannot | can | cannot | can | Partial |
| Venn diagram | cannot | partly | can | cannot | can | can | can | Partial |
| C4 diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| Cynefin diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| Git graph | cannot | cannot | can | cannot | can | can | can | Partial |
| XY chart | cannot | cannot | can | cannot | can | can | can | Partial |
| Wardley map | cannot | cannot | can | cannot | can | can | can | Partial |
| Railroad diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| ZenUML diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| Event modeling diagram | cannot | cannot | cannot | cannot | can | can | cannot | Render only |
| Ishikawa diagram | cannot | cannot | can | cannot | can | can | can | Partial |
| Tree view | cannot | cannot | can | cannot | can | can | can | Partial |
A filled tick means the app can do it for that family; a ring with a tick means it finds it but cannot yet apply it; an empty ring means it cannot.
Continuously updated — this table is read from the app’s own source and re-checked with every release. The latest is Mernyx 1.0.0, released October 22, 2026. See the changelog
What the columns mean
Four of them are about the canvas, three about the source editor, and the last one sums the canvas side up.
- Structure
- Add, delete and connect shapes on the canvas — the axis the flowchart is built around. Where it is ticked, a diagram can be reshaped by dragging, and the Mermaid source is rewritten to match.
- Style
- Change fill, border, text colour, line width and opacity in the properties inspector. A ring with a check means the app finds your style rule but cannot yet say which shape it belongs to, so the appearance section is not there.
- Rename
- Change a piece of text where it sits on the canvas. A name that appears more than once in the source is refused on purpose — changing one place would point the other places at the wrong text.
- Numbers
- Change a number: a pie slice, a treemap leaf, the weight on a sankey link.
- Highlighting
- The source editor knows this family’s own keywords, so its statements are coloured as keywords instead of as plain text.
- Formatting
- Format Document (⌥⌘I) lays this family’s source out — whitespace and indentation. Where it is not ticked, the command stays greyed out for that family.
- Focus sync
- Put the caret on a name in the source and the matching shape is selected on the canvas and scrolled into view. It needs the same mapping renaming needs — the app can only select an element it can identify in the source — so these two columns agree on every family today.
- Verdict
- Full editing means structure, style and rename are all there on the canvas. Render only means there is nothing on that family’s canvas to change. Partial means some of them are.
Read this with the table
It is not about your file.
Your .mmd is a text file. Opening it, editing the source, formatting it, previewing it and exporting PNG, SVG or PDF work on every one of the 34 families, in the free build too. “Render only” describes the canvas, not the file.
“Can rename” is not “rename everything”.
Where the column says a family can be renamed, it means at least one label on the canvas can be changed in place. Names that repeat in the source are refused, because a rename that moved the wrong occurrence would look like it worked.
The app says the same thing, in place.
In the app, an action a family cannot do is not offered at all — the menu item is not there. Where an action is only unavailable right now (compiling, a syntax error), it is greyed out rather than left to fail silently. This page is that list written down.
Questions
Does “render only” mean I cannot edit the file at all?
No. The source editor edits every family — the file is text, and opening, editing, formatting, previewing and exporting work on all 34 in the free build. “Render only” is about the canvas: for that family there is no shape on it to move, restyle or rename.
Why can only some families be edited on the canvas?
Because each family’s diagram is drawn from its own syntax, and the canvas editor writes back into that syntax. A family needs a statement model for its own grammar before a shape can be dragged and the source rewritten correctly. The table says which families have that today.
What do the source-side columns cost?
Nothing — they are in the free build. Highlighting, formatting and focus sync are not among the things the licence gates, which is the whole set of structure editing, style editing, label editing, the assistant and the export tiers.
Where do these readings come from, and how current are they?
They are read out of the app’s own source: the per-family capability table, the families whose diagrams have replaceable labels, the families with an editable number, the keyword tables, and the formatting judgement. The site re-reads them and compares them against this page, and the check names any family that has moved — so the table cannot quietly go stale.
Will more families get full canvas editing?
This page is a reading of the current build, not a roadmap. What a release brings is in the changelog, and a family that gains editing appears in this table when it ships.
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.