Markdown guide

Everyday Markdown

# Document title

## Section

**Bold**, *italic*, and ~~removed~~.

- First item
- Second item

1. First step
2. Second step

- [x] Done
- [ ] Next task

| Feature | Status |
| --- | --- |
| Live preview | Ready |
| Local recovery | Ready |

[Example](https://example.com)

![Alt text](https://example.com/image.png)

Use `inline code`.

```js
const message = "Hello";
```

The area is $A = \pi r^2$.

$$
E = mc^2
$$

```mermaid
flowchart LR
  A[Write] --> B[Preview]
  B --> C[Save a file]
```

Open and save documents

Use File → Open files, or drop .md, .markdown or .txt files into the workspace. Each file opens in its own tab; the current document is not replaced. New documents start empty. UTF-8 files up to 2 MiB are supported, with up to 20 tabs.

Save writes to a selected local file when the browser supports it and permission is granted. Otherwise it starts a Markdown download. A download request does not confirm that a file was saved on disk. Save as lets you choose a new destination. After a reload, a previously opened file must be opened again to reconnect direct saving.

Browser recovery is not a file backup

Recovery saves open documents and tab state in this browser. All interface languages share the same workspace. A tab’s dot tracks changes since the last file save or Markdown download request, not the browser recovery status.

Private browsing, storage eviction and clearing site data can remove recovery copies. Save important documents to files. Closing a modified tab asks for confirmation; closing all documents removes their recovery copies after confirmation. Unsaved changes in another browser tab are not merged automatically.

A comfortable workspace

Use the second-row controls to switch between split view, source only and preview only. In split view, the preview follows only deliberate editor scrolling. Scrolling the preview or typing in the source does not move the other pane. Reading position is preserved by matching Markdown blocks as content changes; large rewrites and deleted sections use a nearby surviving block. Turn following off for fully independent panes.

The outline button opens document headings without a permanent sidebar. The settings menu offers System, Light and Dark themes, a 14–24 px editor text slider, system monospace or sans serif, line numbers and rendering switches. Existing text-size choices are kept; new workspaces default to 16 px. The examples button offers searchable snippets with Copy and Insert. The table button opens a columns-by-rows picker; the selected row count includes the header. Ctrl/Command + F searches the source. Use Tab to leave the editor and arrow keys to move between formatting buttons.

For documents above 250,000 UTF-16 code units or 10,000 line breaks, automatic preview is paused to protect typing responsiveness. Use Refresh preview for a deliberate update. Editing and Markdown saving remain available.

Equations

Inline equations use $...$ or \(...\). Display equations use $$ on separate lines, or \[ and \] on separate lines. Backtick code is never treated as math. Escape a currency symbol as \$ when it could be mistaken for an equation.

The local KaTeX renderer supports a subset of LaTeX, not complete .tex documents. Output uses native MathML. There are limits of 100 rendered expressions and 4,000 characters per expression. Unsupported or unsafe commands retain their source instead of running scripts or loading external resources.

Mermaid diagrams

A fenced code block labelled mermaid is rendered locally when diagram rendering is enabled. No diagram is sent to a cloud service. The renderer runs inside an opaque-origin sandbox with network and storage access blocked.

Up to 24 diagrams of 12,000 characters each are eligible for rendering. A 200-edge limit and rendering deadlines provide additional protection. Configuration directives and YAML configuration frontmatter inside a diagram are rejected. Invalid or unsupported diagrams stay readable as source.

Move your writing to another app

Copy Markdown copies the source. Copy HTML copies portable HTML markup, keeping equations and diagrams as source. Copy formatted text provides HTML plus plain text, suitable for pasting headings, emphasis, lists and tables into apps that accept rich clipboard content. Exact formatting depends on the receiving app; diagrams and equations remain source for clipboard compatibility.

Export HTML produces a standalone document with local MathML equations and sanitized diagram images when rendering succeeds. It does not require IT Drawer scripts. Print / Save as PDF uses the browser’s print dialog; PDF saving depends on the operating system. External Markdown images remain blocked unless you explicitly allow them for that document.

Offline use and installation

Choose File → Offline & install, then Enable offline while connected. This prepares the editor shell for all supported interface languages and the rendering libraries. Offline files are separate from document recovery. Installation through the browser or Add to Home Screen is optional.

Wait until the menu reports that offline use is ready before disconnecting. The Markdown workspace is supported offline, but remote images, this guide and other IT Drawer tools are not included. Browser storage is not permanent. Updates wait until editor windows close; they do not reload an active document.

Remove offline cache unregisters only the Markdown workers and removes only their application caches. Recovery documents are kept. Close all editor windows after removal. To erase documents too, close them in the editor or clear the site’s browser data.