Notes with math and Mermaid
Notes where math and diagrams just render.
Type an equation as you'd write it in LaTeX, sketch a flow in Mermaid, and see both rendered right in the note — no plugins, no screenshots.
How it works
Type math inline or as a block
Wrap LaTeX in $…$ for inline math or use the Math block for display equations. KaTeX renders it as you type.
Write diagrams as text
Type /mermaid for flowcharts, sequence diagrams and more. The source stays editable; readers see the diagram.
Paste existing markdown
Notes from Obsidian, GitHub or ChatGPT keep their $…$, $$…$$ and ```mermaid blocks — they convert on paste, and every note keeps a Markdown copy.
Real examples
Questions
Which math syntax is supported?
LaTeX, rendered with KaTeX: $…$ inline, $$…$$ or a Math block for display equations, and ```math code blocks.
Which Mermaid diagrams work?
Every diagram type Mermaid renders — flowcharts, sequence diagrams, git graphs and more. Flowcharts can also become editable canvases through the octonote CLI.
Can I publish a note with math and diagrams?
Yes. Publish it as a public page in one click; equations and diagrams render for readers, who don't need an account.
More: Technical explainers · Publish notes as a website · System design notes · Notes and diagrams for Claude Code · Use with Claude Code and Codex
Start your first one free.
Free to start. No credit card, no password.