Really cool. Alexander Grooff (this is based on his go library [0]) did a great job.
[0]: https://github.com/AlexanderGrooff/mermaid-ascii
I think I ran into a bug, the "start" edge is not rendered. This is from https://agents.craft.do/mermaid:
stateDiagram-v2
[*] --> Idle
Idle --> Active : start
Active --> Idle : cancel
Active --> Done : complete
Done --> [*]
┌──────────┐
│ │
│ │
│ │
└─────┬────┘
│
│
│
│
▼
┌──────────┐
│ │
│ Idle │
│ │
└─────┬────┘
▲
│
cancel
│
▼
┌─────┴────┐
│ │
│ Active │
│ │
└─────┬────┘
│
│
complete
│
▼
┌──────────┐
│ │
│ Done │
│ │
└─────┬────┘
│
│
│
│
▼
┌──────────┐
│ │
│ │
│ │
└──────────┘The actual Mermaid ASCII renderer is from another project [0]. This project transliterated it to typescript and added their own theming.
Meanwhile they could've just bundled mermaid-ascii and run it on wasm. But then again probably took Claude less than an hour to port this to TS. The main algorithms are 1:1 conversion.
https://github.com/AlexanderGrooff/mermaid-ascii/blob/master...
https://github.com/lukilabs/beautiful-mermaid/blob/main/src/...
Thanks for the credits!
Added it to https://udiagram.com
While Mermaid gets the limelight, Kroki[1] offers: BlockDiag, BPMN, Bytefield, SeqDiag, ActDiag, NwDiag, PacketDiag, RackDiag, C4 with PlantUML, D2, DBML, Ditaa, Erd, Excalidraw, GraphViz, Nomnoml, Pikchr, PlantUML, Structurizr, Svgbob, Symbolator, TikZ, Vega, Vega-Lite, WaveDrom, WireViz, and Mermaid.
My Markdown editor, KeenWrite[2], integrates Kroki as a service. This means whenever a new text-based diagram format is offered by Kroki, it is available to KeenWrite, dynamically. The tutorial[3] shows how it works. (Aside, variables within diagrams are also possible, shown at the end.)
Note that Mermaid diagrams cannot be rendered by most libraries[4] due to its inclusion of <foreignObject>, which is browser-dependent.
[1]: https://kroki.io/
Tangentially related, I once wanted to render a NetworkX DAG in ASCII, and created phart to do so.
There's an example of a fairly complicated graph of chess grandmaster PGM taken from a matplotlib example from the NetworkX documentation website, among some more trivial output examples in the README at https://github.com/scottvr/phart/blob/main/README.md#example...
(You will need to expand the examples by tapping/clicking on the rightward-facing triangle under "Examples", so that it rotates to downward facing and the hidden content section is displayed)
Edit: See child comments, I misunderstood. Original post below anyway.
--
To me, the diagrams have an uglier default design. A crazy amount of dropdown shadow (in the examples), stretched fonts (front page example). It doesn't matter how many diagram types you support if the generated diagrams aren't good quality.
Mermaids defaults are good enough. They're not amazing, but I'm also not embarrassed to show them to other engineers, stakeholders etc
Edit: KeenWrite looks excellent btw
Maybe I've misunderstood, but isn't the whole point that it outputs to those other formats? So if you like the way Mermaid outputs look, you'd just output to that?
Oh, you're right. I misunderstood. I think it was the comparison to mermaid that threw me, and then I checked out the examples
I’m not entirely sure why there’s a push toward ASCII diagrams (perhaps influenced by AI usage). Mermaid and PlantUML are already text-based representations, and what most users actually want is a rendered diagram in a standard, widely recognized notation—primarily for humans, not machines.
ASCII diagrams are inherently constrained by printable characters, which makes them hard to standardize and limits their expressiveness compared to proper diagram renderers.
I think context matters, often I might be writing docs in a text format that doesn't support mermaid (some readmes for instance, or a print put in a CLI tool) and want diagrams.
In those contexts, rendered mermaid as html isn't an option, so this really does seem like one of the best calls for human readability.
What you mean is that you don't find ASCII diagrams useful. Other people do (see other comments). I find them useful for Org Mode where I prefer to work with just text instead of having to keep separate image files together with my .org files. They're also easier to work with if you need to check them into a Git repo and you don't want to be bothered with something like Git LFS or git-annex. The fact that there are people who want them is enough to explain "why there's a push toward" them (assuming there is actually such a push).
A lot of people primarily use markdown and command-line, and, importantly, so do many coding agents (which seems to be the authors' primary use case).
GFM supports Mermaid.
You can put ASCII diagrams in code comments.
Also Claude code in the terminal can show them.
They don't need a renderer, so they can be embedded in source code comments, or in markdown document without requiring e.g. Gitlab to properly render the document. And even then, they're still "rendered" when editing said markdown document.
I love ASCII diagrams! The fact that I can write a diagram that looks equally wonderful in my terminal via cat as it does rendered on my website is incredible.
A good monospaced font and they can look really sharp!
I will definitely give this tool a shot.
I will also shout out monodraw as a really nice little application for building generic ASCII diagrams- https://monodraw.helftone.com/
^Unicode.
Importantly they also render in your source code. I love a good diagram at the top of a file.
Wow! It has this:
Subgraph Direction Override: Using direction LR inside a subgraph while the outer graph flows TD.
The last time I checked, Mermaid couldn't render subgraphs in a different direction than the overall graph.
The live demo requires some download of an AI agent platform? I'd really like to try this but not if that's what's required.
The devs should really setup a client-only GitHub Pages for an accessible demo. Judging from skimming the project itself, it's definitely doable without locking into their platform.
I love Mermaid and Markdown as a combination for documentation.
I wonder if we can get the ASCII render to run inside Vim/NeoVim?
Note that by doing ASCII you’re sacrificing possible accessibility; WCAG 1.0 specifically called ASCII images out as a problem in 1999.
(Mermaid isn’t accessible by default either, but there’s current work in that direction: https://github.com/mermaid-js/mermaid/pull/7349)
Just imagined what a garbage would screen reader spit out.
Also see https://arthursonzogni.com/Diagon for text to ascii.
I have a list of text to diagram tools here https://xosh.org/text-to-diagram/ but not many are text to ascii. There are a few text to ascii sequence diagram tools.
Great list, thank you!
If you like Obsidian.md but can't quite recommend it for less technical folks, these devs' Craft notes spaces are a great alternative:
While great for individuals, it's particularly strong out-of-the-box for teams, or even teams of teams with two levels of grouping.
They bring the same ... craft (ahem) ... to the whole product as shown in their Craft Agents or this renderer, with a strong foundation originally started in the Markdown philosophy. Check out the founder's story on their About page for a refreshingly LLM-free backgrounder.
It seems like the ASCII/Unicode mode doesn't work all that well: https://agents.craft.do/mermaid#sample-6
Pair this with Unicode plots[0] and you're set!
Looks awesome, perfect for a feature request for CC [0] I opened a while back.
> Aesthetics — Might be personal preference, but wished they looked more professional
Im sold. Love mermaid but totally agree.
Am I reading this right and it doesn’t need any DOM or browser engine at all? That would indeed be awesome.
The ASCII output is the missing piece for AI-assisted coding workflows. LLMs can spit out Mermaid, but you can't see the diagram inline in a terminal/code-review context. This fixes that.
When I needed to see mermaid diagrams rendered the other day I realized my existing Forgejo instance already supported it so that's what I've been doing. Push to repo and check it out there. Not inline but not a bad place for code reviews. (I am sure all the other forges also support it)
I've had issues with other CLI wrappers there. ASCII output is a nice touch for including diagrams directly in code comments without breaking formatting. Does it handle large graphs well, or does the text wrap get messy? We tried using `graph-easy` for this before but the syntax was annoying. 6.
I get a sense of deja vu. There was another such project posted within the last 3 months, and another within last 6 months. I should have bookmarked them, because at least one of them was an open library (I think).
Looks really useful to document complex applications, I will give it a try.
In the live demo, I am confused about some of the ascii renderings. (Unless I am missing something, they appear incorrect/inconsistent with the SVG.), https://agents.craft.do/mermaid
So for the "All Edge styles"
graph TD
A[Source] -->|solid| B[Target 1]
A -.->|dotted| C[Target 2]
A ==>|thick| D[Target 3]
┌──────────┐
│ │
│ Source ├─thickted─────┐
│ │ │ │
└─────┬────┘ └─────┼────────────────┐
│ │ │
│ │ │
solid │ │
│ │ │
▼ ▼ ▼
┌──────────┐ ┌──────────┐ ┌──────────┐
│ │ │ │ │ │
│ Target 1 │ │ Target 2 │ │ Target 3 │
│ │ │ │ │ │
└──────────┘ └──────────┘ └──────────┘
The Parallel links, example mermaid
graph TD
A[Input] & B[Config] --> C[Processor]
C --> D[Output] & E[Log]
┌───────────┐ ┌────────┐
│ │ │ │
│ Input │ │ Config │
│ │ │ │
└─────┬─────┘ └────┬───┘
│ │
│ │
│ │
│ │
▼ │
┌───────────┐ │
│ │ │
│ Processor ├◄─────────┤
│ │ │
└─────┬─────┘ │
│ │
│ │
│ │
│ │
▼ ▼
┌───────────┐ ┌────────┐
│ │ │ │
│ Output │ │ Log │
│ │ │ │
└───────────┘ └────────┘
The latter one is a rendering issue I think, the right hand side of Processor is being used as an input from Config and an output to Log but the arrows overlap and become ambiguous.
Who’s going to make the rehype plugin?
Nice one! I had my own spin on this issue as well, but from the other angle https://github.com/probelabs/maid
Getting AI to generate valid mermaid diagrams on scale extremely hard. With maid i'm hitting 100% accuracy.
Maid is basically built from scratch mermaid parser, without any dependnecies, which knows how to auto-fix common AI slop diagramming issues.
How is the LaTeX compatibility? Base mermaid's LaTeX compatibility is quite sparse.
This is great, I will definitely make use of this!
very good job nice. i will give a try !
See also graph-easy.online (https://github.com/cjlm/graph-easy-online)