Code Editor

The Code Editor is for text a rich-text editor would ruin: HTML, CSS, JavaScript, TypeScript, JSON, Markdown.

It runs the Monaco engine — the same one behind VS Code — so you get syntax highlighting, bracket matching and real language features rather than a coloured textarea.

Open it

Double-click a document card holding code or HTML.

Or open Extensions → Code Editor and use New HTML document to start fresh.

Three ways to look at it

A view mode control switches between:

Code — the editor alone. For concentrated work.

Split — code on one side, live preview on the other. The preview follows your edits, which is what you want for HTML you are shaping.

Preview — the rendered result alone. For checking, or showing someone.

Saving

Save writes back to the card. The button reports Saved so you know it landed.

Save As writes a new document instead, leaving the original as it was.

Your HTML is not sanitised

This matters and is easy to miss.

The Code Editor treats your HTML as raw — what you write is what is stored and rendered in preview. It is not stripped, rewritten or cleaned up on your behalf.

That is the correct behaviour for a code editor. A tool that quietly removed your <script> tag or rewrote your markup would be useless for the job. But it does mean the preview runs what you wrote, so treat pasted code from elsewhere with the same caution you would anywhere else.

Worth knowing

Files from your computer are read-only. Opened through the Files panel, a file cannot be overwritten — use Save a copy.

Next

• Documents — for prose rather than markup
• Tools — the code card, for short snippets on the workspace