Observable Notebook

Note: This is an unofficial, community-maintained VS Code extension. It is not affiliated with or endorsed by Observable. It wraps Observable's official notebook-kit to bring Observable notebooks into VS Code.

New: Observable Notebook 2.0 Support

This extension now supports the new Observable Notebook 2.0 format! 🎉

Key Features

• Vanilla JavaScript: No need to learn Observable JavaScript dialect
• Open HTML Format: Git-friendly notebooks with clear diffs
• Modern Imports: Support for npm, JSR, and local imports
• Static Site Generation: Build notebooks to static sites
• Backwards Compatibility: Continue using existing .ojsnb format

Quick Start with Observable Notebook

1. Run the Command Palette entry "Observable Kit: Observable Kit Notebook" to scaffold a new notebook
2. Choose a name (e.g., my-notebook) – the command creates my-notebook.onb.html
3. Click Switch to Notebook View (toolbar button or command) to open the interactive editor and start writing vanilla JavaScript with display()
4. Use Switch to Text View any time you want to edit the underlying HTML shell or metadata
5. Run Observable Kit: Build Static Site when you are ready to produce deployable output

HTML File Detection & View Switching

The extension automatically detects Observable notebooks vs regular HTML files and provides seamless switching:

Smart File Opening: When you open an HTML file, VS Code will:

• Regular HTML files: Open in text editor by default
• Observable notebook files: Show a choice dialog - "Select Editor for .html files" with options:
  • Text Editor (default HTML editor)
  • Observable Notebook (interactive notebook view)

Seamless View Switching: Once a file is open, you can switch between views using toolbar buttons:

• 📖 Switch to Notebook View - Appears when viewing Observable notebook HTML as text
• 📝 Switch to Text View - Appears when viewing notebook, switches back to HTML source
• No temporary files - Everything works directly with your original .html files

File Extensions:

• *.html - Can be opened as either text or notebook (VS Code will ask)
• *.onb.html - Reserved for explicit notebook files (opens as notebook by default)

Benefits:

• No workflow interruption - You choose how to open files
• Direct file editing - No temporary files or complex file management
• Flexible switching - Toggle between text and notebook views instantly

Manual Commands (always available):

• Right-click menu: Right-click HTML file in Explorer → "Observable Kit: Open HTML as Observable Notebook"
• Command Palette: "Observable Kit: Convert HTML to Observable Notebook" (permanently renames to .onb.html)

Learn more about Observable Notebook →

Supports

• JavaScript
• Observable JavaScript
• Markdown
• Observable Markdown
• HTML
• SQL
• SVG
• GraphViz (DOT)
• Mermaid
• LaTeX

Recommended Extension Pack

To get the full experience, install this extension as part of the JavaScript Notebook extension pack.

Quick Start with Observable Notebook-Kit

1. Open a notebook-kit notebook (extension .html)
2. Click "Switch to Notebook View" in the text toolbar.
3. Edit, run and save your notebook.
4. Optionally click "Switch to Text View" to go back to the HTML source.

Quick Start with Observable Notebooks

1. Select "OJS: Download Notebook" from command palette.
2. Paste URL from Observable website, for Example: https://observablehq.com/@observablehq/five-minute-introduction
3. Save file to known name and location (Note: Keep the default file extension of "ojsnb").
4. In VS Code open the file.
5. Click "Run All" in the notebook toolbar.

Quick Start with Observable JavaScript (.ojs) | Markdown (.omd)

1. Create a new file with either the .ojs or .omd extension (optional).
2. Open this file in a VS Code editor instance (optional).
3. Select "OJS: Import Notebook" from command palette.
4. Enter https://observablehq.com/@observablehq/a-taste-of-observable for the import URL.
5. Press Ctrl+K V to preview notebook.
6. Select "OJS: Export to HTML" from the command palette.
7. Double click the exported HTML file to view in browser (Note: You may need to host the file on a webserver if it is importing other libraries).

Commands

Legacy commands are prefixed with "OJS"; Notebook Kit commands appear under "Observable Kit" in the Command Palette

Legacy OJS Commands

Command	Shortcut	Description
OJS: Check Syntax	F7	Syntax Check
OJS: Preview Web Page	Ctrl+K V	Preview notebook in an embedded Web Page
OJS: Download Notebook		Download notebook from Observable
OJS: Import Notebook Cells		Import published or shared notebook cells into current document
OJS: Export to HTML		Export as a self contained HTML file
OJS: Export to ECL		Export as a self contained ECL attribute

Observable Notebook Commands

Command	Description
Observable Kit: Create New Notebook	Create a new Observable Notebook HTML notebook
Observable Kit: Preview	Preview notebook using Observable Notebook CLI
Observable Kit: Build Static Site	Build static site from notebooks
Observable Kit: Convert from Legacy	Convert .ojsnb files to Observable Kit HTML format
Observable Kit: Convert HTML to Observable Notebook	Convert HTML file to Observable Notebook format (renames file)
Observable Kit: Open HTML as Observable Notebook	Open HTML file as Observable Notebook (temporary)
Observable Kit: Setup Workspace	Install and configure Observable Notebook

Settings

All settings are prefixed with "ojs." and are available via File -> Preferences -> Settings

Setting	Default	Description
ojs.refreshPreviewOnSave	true	Refresh preview (if visible) when OJS document is saved
ojs.showRuntimeValues	false	Show runtime values as diagnostic info

Sample OJS File (myfile.ojs)

md`# Generator Test`;

function* range(n) {
  for (let i = 0; i < n; ++i) {
    yield i;
  }
}

{
  for (const i of range(Infinity)) {
    yield Promises.tick(1000, i + 1);
  }
}

md`# Import Test`;

import {viewof selection as cars} from "@d3/brushable-scatterplot";
viewof cars;

md`### Selection:
~~~json
${JSON.stringify(cars, undefined, 2)}
~~~
`;

Sample OMD File (myfile.omd)

# Generator Test

_Simple Generator test_

```
function* range(n) {
  for (let i = 0; i < n; ++i) {
    yield i;
  }
}

{
  for (const i of range(Infinity)) {
    yield Promises.tick(1000, i + 1);
  }
}
```

# Import Test

_Simple Import Test_

```
import {viewof selection as cars} from "@d3/brushable-scatterplot";
viewof cars;
```

### Selection:

```json
${JSON.stringify(cars, undefined, 2)}
```

Credits

This extension would not have been possible without the following:

• observablehq/parser
• observablehq/runtime
• observablehq/inspector
• observablehq/stdlib
• @hpcc-js/observablehq-compiler

Recommended Extensions

Other recommended extensions for working with Observable notebooks formats in VS Code:

Extension	Description
Observable JS Notebook Inspector	VS Code extension for Interactive Preview of Observable JS Notebooks, Notebook Nodes, Cells and source code