Blob Notebook
Switch guideJavaScript editor

JAVASCRIPT EDITOR

A JavaScript editor for the snippets you keep coming back to.

Draft a helper function, save a useful array transformation, or clean up pasted JavaScript. Keep .js code in a local notebook with syntax highlighting and formatting, alongside the notes that explain it.

Open editor

Free to use · No account needed · Saved in this browser

ready-items.js JavaScript
const items = [
  { name: 'Guide', ready: true },
  { name: 'Demo', ready: false },
];

const readyNames = items
  .filter((item) => item.ready)
  .map((item) => item.name);
A small filtering example to edit or keep as a reusable JavaScript snippet.Try this example

EDIT IN YOUR BROWSER

Your local draft

The notebook’s editing tools, right here. Save to notebook when you want a named copy.

Open full editor

Enable JavaScript to edit here, or open the full editor above. The example and guide are always available.

This draft is shared with the full editor for this task and stays separate from named notes. Export a copy or save to notebook to include it in a notebook backup. This editor page and its tools reopen offline after the editor reports readiness. Informational and privacy guides need a connection.

A FEW SIMPLE STEPS

Get started

  1. Open the notebook and create a JavaScript note using the language chooser.
  2. Paste your .js source or import a JavaScript file.
  3. Use the code tools to format it, search within it, or save a useful selection as a snippet.
  4. Download the note or copy the edited source back to your project for testing.

Open editor takes you to the draft on this page. Paste or open a source file, or choose Try this example. Save to notebook keeps a named copy with your notes. Your workspace style stays unchanged.

Give a useful fragment a home

Name a note after the problem it solves and tag it for the project that needs it. The snippet library can insert saved code into the focused editor; you can also save a selected fragment as a custom snippet.

Use Format to tidy supported JavaScript syntax and find and replace to update repeated identifiers. Comparison panes help you inspect an old helper beside a revised version.

Editing and execution are separate steps

JavaScript mode edits source without running the .js note. For a small browser example, put your script inside an HTML note and use its sandboxed preview. The notebook does not provide Node.js, install npm packages, or build a project.

If your example is mostly an API payload, choose JSON mode to open its table visualizer. Choose TypeScript when you need type annotations in the source.

A few questions

Can I run JavaScript here?

A .js note edits source without executing it. Scripts inside an HTML note can run in its sandboxed preview. Node.js and package installation are not available.