Hey,
I write a tech blog and I need to create lots of diagrams for it. I like using Mermaid, but I quickly ran into the same frustrating pattern with most of the existing editors and renderers: the free options were either too limited or came with barriers that slowed me down. I wanted something simple: just open the page, paste/type in Mermaid code, preview the diagram, and export it without worrying about limits or accounts.
Here are some concrete problems I ran into with other tools:
- Mermaid Live Editor (the official one): Great for quick editing, but exporting diagrams is capped by a rate limit on their free tier. After a handful of exports, I’d get the dreaded “free tier limit exceeded” message.
Kroki.io: Supports rendering, but running it online requires trusting a shared service with my diagrams. Hosting it myself means extra setup, Docker, and server resources — not ideal if I just want to save a few diagrams.
- Excalidraw & Lucidchart: Both have nice UIs, but they’re general diagramming tools, not native Mermaid editors. Lucidchart especially locks useful features (like unlimited diagrams or high-quality export) behind a paid plan.
- Other browser-based tools Almost all I tried had some kind of paywall, signup requirement, or watermark on exports. For something as text-based and simple as Mermaid, that felt unnecessary.
So I built my own tool with a few core principles:
- No limits: you can create, edit, and export as many diagrams as you want.
- No signup: the tool works straight from the browser, nothing to install.
- No tracking: privacy-friendly, just you and your diagrams.
- Open source:
https://github.com/gkoos/mermaid-editor
Now this is a very simple v0.0.1 and needs a lot of refinement, but hopefully it can be useful to some even in its current state.