Readdown vs MDViewer
Two free native Markdown readers for Mac — similar goals, different depth
Quick Overview
Readdown is a free, native Markdown reader for macOS by a solo developer. It focuses on clean rendering with QuickLook integration, offline Mermaid and KaTeX support, and a minimal interface. At 6.3 MB, it is one of the smallest Markdown apps available.
MDViewer is a free native Markdown viewer with inline editing, Git history, smart table of contents, tabs, file tree, and Finder QuickLook. The Lite version is free; Pro adds editing, Git, and PDF export for $9.99.
These two apps are the closest competitors in the macOS Markdown space. Both are free, native Swift apps with QuickLook and Mermaid support. The difference is depth: MDViewer has significantly more features for working with Markdown files day-to-day.
Feature Comparison
| MDViewer | Readdown | |
|---|---|---|
| Price | Lite: Free / Pro: $9.99 | Free |
| Platform | macOS 13+ | macOS 13+ |
| Technology | Native SwiftUI | Native Swift |
| App size | ~15 MB | 6.3 MB |
| QuickLook | Yes | Yes |
| Inline editing | Yes (double-click to edit) | No |
| Git history & diff | Yes (built-in) | No |
| Table of contents | Yes (auto, tracks scroll) | No |
| Tabs | Yes | No |
| File tree | Yes | No |
| Collapsible headings | No | Yes |
| Mermaid diagrams | Yes (interactive SVG with zoom) | Yes (offline since v1.9) |
| Math (KaTeX/LaTeX) | Yes (KaTeX) | Yes (KaTeX, offline since v1.16) |
| Syntax highlighting | Yes (full language support) | Yes (19 languages) |
| Live reload | Yes | Yes |
| PDF export | Yes (⌘⇧E) | Yes (print/export) |
| Find in document | Yes | Yes |
| Zoom | Yes | Yes |
| Themes | Light & Dark (system) | Light & Dark |
| Distribution | Website & Mac App Store | GitHub only |
| Source code | Closed | Source-available (no redistribution) |
When to Choose MDViewer
- You work with Git repositories and want to see file history and diffs without leaving the viewer
- You read long documents and need a table of contents that tracks your scroll position
- You keep multiple files open at once and want tabs instead of separate windows
- You want to browse a project with a file tree sidebar
- You need inline editing to make quick fixes without switching to a code editor
- You need broad syntax highlighting beyond the 19 languages Readdown supports
- You prefer installing from the Mac App Store with automatic updates
When to Choose Readdown
- You want the smallest possible app — Readdown is 6.3 MB, less than half of MDViewer
- You like collapsible headings to fold sections of long documents
- You want a pure reader with no editing features or complexity
- You prefer apps with publicly available source code you can inspect
- You do not need Git integration, tabs, or a document outline
The Biggest Differences
On paper, Readdown and MDViewer look similar. Both are free, both are native, both handle Mermaid and KaTeX. But day-to-day use reveals significant gaps.
Document navigation. When you open a 500-line README, MDViewer’s smart table of contents shows every heading in the sidebar and highlights your current position as you scroll. Readdown has collapsible headings in the document body, which is useful for hiding sections you’re not reading, but it does not give you an overview of the entire document or let you jump to a specific section instantly.
Working with multiple files. MDViewer lets you open files in tabs within one window and browse related files in a file tree. Readdown opens one file at a time. If you regularly switch between a README, a CHANGELOG, and a few spec files, tabs save meaningful context-switching time.
Git awareness. MDViewer Pro shows the complete commit history for any file in a Git repository, with color-coded diffs. If you want to know when a section of documentation changed or who modified it last, you can find out without leaving the viewer. Readdown has no Git integration.
Syntax highlighting depth. Readdown supports 19 languages for code block highlighting. MDViewer supports a much broader set. If you read documentation with code examples in less common languages, MDViewer is more likely to highlight them correctly.
FAQ
Is Readdown open source?
Readdown’s source code is publicly available on GitHub, but its license prohibits redistribution. This means you can read the code but cannot fork it, modify it, or distribute your own version. It is source-available, not open source in the OSI sense.
Does Readdown have a document outline or sidebar?
No. Readdown does not have a table of contents sidebar or document outline. It does support collapsible headings within the document body. MDViewer has a smart TOC that automatically generates from headings and highlights the current section as you scroll.
Can Readdown show Git history?
No. Readdown has no Git integration. MDViewer Pro shows the full commit history and color-coded diffs for any file inside a Git repository, directly in the sidebar.
Which is smaller, Readdown or MDViewer?
Readdown is smaller at 6.3 MB compared to MDViewer’s approximately 15 MB. Both are lightweight native apps — neither comes close to the 100+ MB footprint of Electron-based editors.
Try MDViewer
MDViewer Lite is free with core viewing features. Pro adds editing, Git history, and PDF export for $9.99. Download and see how the extra features fit your reading workflow.
Requires macOS 13.0 or later. Intel and Apple Silicon.