[FEATURE] HTML viewer and .md edit in Claude Desktop App

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When working in the Claude Desktop app on macOS, there's no built-in way to (1) preview HTML or web-page output as a rendered page, or (2) edit Markdown files directly in the app. Today, when Claude produces HTML or a .md file, I have to leave the app — open the file in a browser to see the rendered result, or open a separate editor to tweak the Markdown. This breaks the flow of an otherwise tightly integrated experience and makes quick iteration slow.
This hits hardest for a major group of new Claude Desktop users: non-technical people — not developers or "tech natives" — who are encountering .md files for the first time and want to use Claude to its full potential. Many currently live in tools like Google Drive and have no way to view or edit Markdown files there at all. For this audience, the current experience is a wall: Claude produces a .md file or an HTML page, but there's no native way to read the rendered result or make a quick edit without installing a developer-oriented editor and learning new tooling. That friction stops a lot of would-be users before they get any value.
Adding in-app Markdown editing and HTML preview would remove that wall. It lets someone open, read, and tweak a .md file the same way they'd edit a Google Doc, and see HTML render as a finished page — no external tools, no technical setup. This would open Claude Desktop up to a much wider audience of non-technical users who are eager to unlock Claude's capabilities but are currently blocked by file-format friction.

Proposed Solution

Additions to the Claude Desktop app for Mac:

Markdown (.md) editing & HTML / web page preview
A live, rendered preview pane for HTML content that Claude generates or that exists in a connected folder.
Toggle between rendered view and raw source.
Auto-refresh when the underlying file changes, so iterating on a page with Claude updates the preview in place.
Support for self-contained HTML (inline CSS/JS) at minimum, which covers most generated artifacts.
Open and edit .md files directly in the app with a live rendered preview alongside the source.
Save changes back to the original file in the connected folder.
Standard editing niceties: syntax highlighting for Markdown, and a side-by-side or toggleable rendered view.

Alternative Solutions

Opening generated HTML in an external browser and .md files in a separate editor (VS Code, Typora, etc.) — works, but defeats the purpose of an integrated desktop app and slows the edit/preview loop.
Copy-pasting content out of the chat into another tool — error-prone and loses the connection to the file on disk.

Priority

Critical - Blocking my work

Feature Category

Developer tools/SDK

Use Case Example

Adding in-app Markdown editing and HTML preview would remove that wall. It lets someone open, read, and tweak a .md file the same way they'd edit a Google Doc, and see HTML render as a finished page — no external tools, no technical setup. This would open Claude Desktop up to a much wider audience of non-technical users who are eager to unlock Claude's capabilities but are currently blocked by file-format friction.

Additional Context

This hits hardest for a major group of new Claude Desktop users: non-technical people — not developers or "tech natives" — who are encountering .md files for the first time and want to use Claude to its full potential. Many currently live in tools like Google Drive and have no way to view or edit Markdown files there at all. For this audience, the current experience is a wall: Claude produces a .md file or an HTML page, but there's no native way to read the rendered result or make a quick edit without installing a developer-oriented editor and learning new tooling. That friction stops a lot of would-be users before they get any value.