MacMD Viewer: a read-only Markdown viewer for reviewing what Claude writes

Disclosure: The developer of MacMD Viewer gave me a free licence. They didn't ask for a positive review and didn't see this post before it went up. I don't earn anything from links in this post.

Most of the Markdown I read these days, I didn't write. I wrote "Writing Effective Claude Skills" around one idea: keep the process in SKILL.md, keep the knowledge in REFERENCE.md, and put sample inputs and outputs in a folder of their own. That works well, but now there's a pile of .md files that Claude is constantly rewriting, and I need to read them without changing them by accident.

That's where MacMD Viewer fits. It's a Markdown viewer, not an editor, and that turns out to be the whole point.

What it is

MacMD Viewer is a native macOS app built in SwiftUI. It does two things:

1. Quick Look in Finder. Select a .md file and press space, and you get a formatted preview instead of raw text.
2. A viewer window with a document outline, syntax-highlighted code blocks, tables, Mermaid diagrams, and automatic reloading when the file changes on disk.

It needs macOS 14 or later. It's a one-time purchase of $19.99, and it's also included in Setapp. I tested version 1.2.2.

Why read-only is a feature

When Claude is editing a skill, I don't want a second editor holding the same file open. Editors autosave, reformat whitespace, and argue with the agent over who wrote last. A viewer avoids all of that. Claude writes, the window reloads, and I read.

Quick Look is the part I use most

Being able to page through a skill folder in Finder (SKILL.md, REFERENCE.md, then the files in examples/) and press space on each one is the quickest way I've found to check that a skill still hangs together. You don't open a window or an app. You just see the rendered file.

Rough edges

• The price. $19.99 is fair for a polished native app, but VS Code's preview and Obsidian already render Markdown for free. You're paying for Quick Look, native speed, and not having to open an editor.
• No link navigation. Some users want to click relative links between .md files, go back, and browse a folder of docs the way GitHub does. For a skill folder that cross-references REFERENCE.md, I'd want that too.
• No raw-source toggle. Sometimes I want to see the exact Markdown Claude wrote, such as front matter or odd whitespace. The developer has said this is on their list.

Verdict

If you're on a Mac and you spend your day reading Markdown that an agent writes (skills, plans, specs, READMEs), MacMD Viewer is a small, focused tool that stays out of the way. Quick Look alone makes Finder a decent way to browse a skills folder. If you edit Markdown more than you read it, stick with your editor's preview.

macmdviewer.com