MD-Viewer vs MDViewer
Two free Markdown viewers — very different under the hood
Quick Overview
MD-Viewer (by M25) is a free Markdown viewer available on macOS and Windows. It renders Markdown with syntax highlighting, has a dark mode, and can export to PDF. At 124.8 MB, it is a notably large download for a viewer app.
MDViewer (by Crocopliers) is a free native macOS Markdown viewer built with SwiftUI. At ~15 MB, it is roughly 8x smaller. It adds QuickLook integration, Mermaid diagrams, Git history, live reload, and tabs.
Both are free. The difference is in what you get for the disk space and which platform you need.
Feature Comparison
| MDViewer | MD-Viewer | |
|---|---|---|
| Price | Lite: Free / Pro: $9.99 | Free (no paid tier) |
| Platform | macOS only (13.0+) | macOS (10.13+), Windows |
| Technology | Native SwiftUI | Unknown (bundled runtime) |
| App size | ~15 MB | 124.8 MB |
| Finder QuickLook | Yes | No |
| Git history & diff | Yes (built-in) | No |
| Mermaid diagrams | Yes (interactive SVG with zoom) | No |
| Math (KaTeX) | Yes | No |
| Table of contents | Yes (auto, tracks scroll) | Yes (auto sidebar) |
| Tabs | Yes | No |
| Inline editing | Yes (double-click to edit) | No |
| Live reload | Yes | No |
| Dark mode | Yes (system preference) | Yes (light/dark toggle) |
| Syntax highlighting | Yes | Yes (100+ languages) |
| PDF export | Yes (⌘⇧E) | Yes |
| In-document search | Yes | Yes |
| Launch speed | Instant (< 1 second) | Slower (larger runtime) |
| RAM usage | ~40 MB idle | Higher (bundled runtime) |
When to Choose MDViewer
- You want QuickLook — preview .md files in Finder by pressing Space, without opening any app
- You need Mermaid diagrams or KaTeX math rendered in your Markdown files
- You want Git history and diffs built into your viewer
- You prefer a small, fast app — 15 MB vs 124.8 MB, with instant launch
- You want tabs and live reload for working with multiple files
- You need inline editing — double-click any section to make quick changes
When to Choose MD-Viewer
- You need a Markdown viewer on Windows — MDViewer is macOS only
- You run an older Mac (macOS 10.13–12) that MDViewer does not support
- You want something completely free with no paid tier or upsell — MD-Viewer has no Pro version
- You only need basic rendering without Mermaid, math, or Git features
App Size: Why It Matters
The most striking difference between these two viewers is size. MDViewer is ~15 MB. MD-Viewer is 124.8 MB — over 8 times larger.
MDViewer is a native SwiftUI app. It uses macOS system frameworks directly for rendering, layout, and text handling. There is no bundled engine — what macOS provides is enough.
MD-Viewer’s 124.8 MB download strongly suggests a bundled runtime — likely an Electron-style framework that packages a full browser engine inside the app. This is a common approach for cross-platform apps: it lets the same codebase run on macOS and Windows, but the trade-off is a much larger download and higher resource usage.
For a Markdown viewer — an app that renders text, headings, code blocks, and tables — the size difference is hard to justify. You are downloading 125 MB to do what a 15 MB native app does with more features and faster performance.
The QuickLook Advantage
One of MDViewer’s most practical features is Finder QuickLook. Select any .md file in Finder and press Space — the rendered Markdown appears instantly in a preview panel. No app launch, no window management. Press Space again to dismiss.
MD-Viewer does not provide a QuickLook extension. To preview a Markdown file, you must open the full application. For developers and writers who check Markdown files frequently throughout the day, QuickLook eliminates the overhead of launching a dedicated app for a quick look at a file’s contents.
FAQ
Is MD-Viewer the same as MDViewer?
No. MD-Viewer is made by M25 and is available on macOS and Windows. MDViewer is made by Crocopliers and is a native macOS-only app built with SwiftUI. They are completely separate products with similar names.
Why is MD-Viewer 124.8 MB when MDViewer is only 15 MB?
MDViewer is a native SwiftUI app that uses macOS system frameworks directly, so it does not need to bundle a rendering engine. MD-Viewer’s 124.8 MB size suggests it bundles a runtime environment to render Markdown.
Does MD-Viewer support Mermaid diagrams?
No. MD-Viewer does not render Mermaid diagrams. MDViewer renders Mermaid diagrams as interactive SVGs with zoom, directly in the preview.
Can I use MD-Viewer on Windows?
Yes. MD-Viewer is available on macOS and Windows. MDViewer is macOS only. If you need a Markdown viewer on both platforms, MD-Viewer is the option between these two.
Try MDViewer
MDViewer Lite is free — with QuickLook, Mermaid, and smart TOC included. Pro adds editing, Git history, and PDF export for $9.99. Download and compare for yourself.
Requires macOS 13.0 or later. Intel and Apple Silicon.