Capability matrix
Everything Koala renders, in one page.
Koala is built for technical Markdown. That means diagrams, syntax-highlighted code, full GitHub-flavored Markdown and clean export. Here is the complete list.
Diagrams
Mermaid and D2, rendered inline.
Fenced ```mermaid and ```d2
blocks render into the document. No plugins, no preview pane swap.
| Engine | Diagram type | Notes |
|---|---|---|
| Mermaid | Flowchart | Top-down, left-right, branching |
| Sequence diagram | Actors, messages, loops, notes | |
| Class diagram | Inheritance, composition | |
| State diagram | State machines, transitions | |
| Entity-relationship | Schemas, cardinality | |
| User journey | Step-by-step flows | |
| Gantt chart | Schedules, milestones | |
| Pie chart | Proportional breakdowns | |
| Quadrant chart | 2x2 matrices | |
| Requirement diagram | Spec-style requirements | |
| Git graph | Branching, commits | |
| Mindmap | Hierarchical idea trees | |
| Timeline | Sequenced events | |
| Sankey | Flow / weight diagrams | |
| XY chart | Plots, scatter, bar | |
| Block diagram | Logical blocks | |
| Packet diagram | Byte/bit layouts | |
| Kanban | Boards | |
| Architecture | System architecture | |
| C4 | Context, container, component | |
| D2 | Flowchart | Layered, auto-layout |
| Sequence diagram | Lifelines, messages | |
| Class / shape graphs | Custom shapes, containers | |
| ER diagram | Tables and relationships | |
| Free-form graphs | Any node-edge diagram D2 supports |
Syntax highlighting
180+ languages, no configuration.
Fenced code blocks pick up syntax highlighting automatically. The full list comes
from highlight.js - common languages shown below,
everything else is supported too.
Backend / systems
- go
- rust
- c
- c++
- java
- kotlin
- scala
- elixir
- erlang
- haskell
- ocaml
- nim
- zig
Web / frontend
- typescript
- javascript
- jsx
- tsx
- html
- css
- scss
- less
- svelte
- vue
Scripting
- python
- ruby
- perl
- lua
- bash
- zsh
- powershell
- awk
Data / config
- sql
- graphql
- json
- jsonc
- yaml
- toml
- xml
- ini
- protobuf
Infra / DevOps
- dockerfile
- nginx
- makefile
- cmake
- diff
- patch
Mobile / native
- swift
- objective-c
- dart
- kotlin
- java
Anything highlight.js supports works - including
assembly, R, MATLAB, Julia, F#, Clojure, Lisp, Scheme, Smalltalk, Pascal, Fortran,
COBOL and many more.
Markdown
Full GitHub-flavored Markdown.
Koala uses remark-gfm, so anything that renders on
GitHub renders here. Plus a few extras for navigation and diagrams.
| Feature | Supported | Notes |
|---|---|---|
| Headings (H1-H6) | Yes | Anchor IDs auto-generated for in-doc links |
| Bold / italic / strikethrough | Yes | GFM strikethrough included |
| Ordered & unordered lists | Yes | Nested to any depth |
| Task list checkboxes | Yes | Rendered as checkboxes in reader |
| Tables | Yes | Alignment, header rows |
| Images | Yes | Relative paths resolve against the file |
| Links | Yes | External + relative cross-file Markdown links |
| Auto-linked URLs | Yes | Via GFM autolink |
| Blockquotes | Yes | Nested supported |
| Inline code | Yes | Distinct styling from block code |
| Fenced code blocks | Yes | Syntax highlighted, copy button |
| Horizontal rules | Yes | --- |
| Heading anchors / ToC | Yes | Rendered as a clickable outline |
| Mermaid blocks | Yes | Rendered inline |
| D2 blocks | Yes | Rendered inline |
| Cross-file Markdown links | Yes | Click ./other.md to jump |
Export
Share the rendered output.
When you need to hand a doc to someone who doesn’t have Koala, export it.
| Format | What you get | Best for |
|---|---|---|
| HTML | Self-contained, lossless render of the document with all styling | Sharing, archiving, posting on an intranet |
| Image-based PDF of the rendered page | Email, formal handover, printing | |
| Open in browser | Rendered HTML opens in your default browser | Quick preview, browser-native Print -> Save as PDF |
Open any Markdown folder and see for yourself.
Download Koala free during early access. Drop a folder in and every capability above works out of the box.
Download Koala free