v0.1.0 · macOS & Windows · free forever

MDHero.
Write anywhere,
read here.

A beautiful, native Markdown viewer for macOS and Windows.

Free. Open source. ~11MB. No accounts, no uploads — just your files, rendered the way they deserve.

Download for macOS Download for Windows

Requires macOS 12+ or Windows 10+. Universal binary.

complete-test.md — MDHero

complete-test.md

README.md

claude-plan.md

Getting started

MDHero renders your Markdown the way you wrote it — headings with breathing room, code with real syntax colors, tables that actually align. No setup. No configuration. Open a file and read it.

Quick start

Download the app, open any .md file, and start reading. Or drag-and-drop, or use Cmd+O.

Example

 typescript import { readFile } from 'fs/promises';
async function loadDocument(path: string) { const content = await readFile(path, 'utf8');
return content;
} 

What makes MDHero different

Three reasons you'll leave it on your Dock.

Your files stay local

Everything runs on your machine. No uploads, no cloud, no accounts. Open a file and read it — that's it.

Beautiful by default

Apple-inspired typography with dark mode, syntax highlighting for 25+ languages, KaTeX math, and Mermaid diagrams.

Built for the AI era

Paste ChatGPT or Claude output directly — MDHero auto-detects and cleans up LLM formatting. Also reads Claude Code plans.

Features

Everything a markdown file needs. Nothing it doesn't.

Six small ideas that make a difference every time you open a file.

01 — Sources

Open anything.

Local files, GitHub URLs, pasted markdown, or Claude Code plans — one app reads them all.

Local files GitHub URLs Paste ~/.claude/plans

Quick actions

Browse files

Open URL

Pin folder

Pinned folders

~/Documents/notes

meeting-2026-04-18.md

product-brief.md

weekly-review.md

~/Code/mdhero/docs

~/.claude/plans

02 — Navigation

Tabs, TOC, and your muscle memory.

Multiple tabs with drag-to-reorder. Table of Contents sidebar. Search with ⌘F. Vim keybindings when you want them.

Drag-to-reorder TOC sidebar Vim keys

brief.md

notes.md

api.md

readme.md

Product brief

Owner: Vaibhav · Status: Draft

Summary

A one-page overview of what we're building and why it matters to the people using it every day.

Goals

Three outcomes, each measurable within a quarter.

03 — Code

Syntax highlighting that reads like a book.

25+ languages with beautiful code blocks. Copy button on hover. Dark and light themes that agree on what a string should look like.

25+ languages Copy on hover Dark & light themes

 typescript // Count tokens in a markdown document import { tokenize } from './lexer';
export async function countTokens(path: string) { const text = await fs.readFile(path, 'utf8');
const tokens = tokenize(text);
return tokens.filter(t => t.type !== 'whitespace').length;
} 

 python def render(path: str) -> str:
with open(path) as f:
        doc = f.read()
return markdown.to_html(doc, extensions=['tables', 'fenced_code'])

04 — Math & diagrams

Equations and flowcharts, rendered inline.

KaTeX renders LaTeX equations. Mermaid renders flowcharts, sequence diagrams, and more — with no plugins, no extra steps.

KaTeX Mermaid

e^iπ + 1 = 0 · P(A|B) = P(B|A) · P(A)P(B)

05 — LLM paste mode

Paste raw LLM output. Read real markdown.

MDHero auto-detects escaped \n characters and stray backslashes in LLM output and renders clean markdown — no manual cleanup.

ChatGPT Claude Auto-unescape

Paste markdownesc to close

Paste

Open URL

# Plan\n\n1. Parse tokens\n2. **Render** tree\n\n```ts\nconst x = 1;\n```

LLM mode — unescape \n

06 — Pins

Pin your folders. Open with one click.

Pin frequently-used directories for instant access to every markdown file inside — no more hunting through Finder.

Folder pins Recent files

Pinned folders

~/Desktop/work

LANDING_PAGE_BRIEF.md

CLAUDE.md

release-notes-1.0.md

~/obsidian-vault

~/.claude/plans

Recent files

complete-test.md 2m ago

architecture.md yesterday

roadmap.md 3d ago

Keyboard shortcuts

For when your hands don't want to leave the keyboard.

Browse files⌘O

Paste markdown⌘⇧V

New tab⌘T

Close tab⌘W

Switch tabs⌘1…9

Search⌘F

Raw markdown view⌘U

Zoom in / out / reset⌘=/-/0

Scroll down / upj/k

Top / bottomgg/G

On Windows, ⌘ becomes Ctrl.

Open source, MIT licensed.

Crafted with care for people who live in their markdown.

Star on GitHub View source

Built with in open source.

MDHero.Write anywhere,read here.

Getting started

Quick start

Example

Three reasons you'll leave it on your Dock.

Your files stay local

Beautiful by default

Built for the AI era

Everything a markdown file needs. Nothing it doesn't.

Open anything.

Quick actions

Pinned folders

Tabs, TOC, and your muscle memory.

Product brief

Summary

Goals

Syntax highlighting that reads like a book.

Equations and flowcharts, rendered inline.

Paste raw LLM output. Read real markdown.

Pin your folders. Open with one click.

Pinned folders

Recent files

For when your hands don't want to leave the keyboard.

Open source, MIT licensed.

MDHero.
Write anywhere,
read here.