Checkout plan
Architecture
Tasks
- Payment steps
- Coupon tests
MDLumen for macOSThe Markdown reader for Mac.
The Markdown reader for Mac.
Light up every .md.
Your AI tools write in Markdown: plans, specs, READMEs. MDLumen turns them into clean, readable documents, and opens your whole project in tabs with search across every file.
- $6.99 once
$13.99 - 1 licence, 3 Macs
- 14-day refund
- Works offline
- macOS 14 Sonoma or later
A plain .md file becomes a clean, readable document.
Works with the Markdown files made by
- Claude Code
- Cursor
- ChatGPT
- Codex
- GitHub Copilot
- Windsurf
ONE FILE IS EASY. A PROJECT IS BETTER.
Read the whole project, not one file at a time.
1
Open a folder
Drop your project or docs folder on MDLumen. Every .md file inside shows up in the sidebar.
2
Read in tabs
Open the plan, the spec and the README side by side in tabs, rendered the way they were meant to look.
3
Find anything
Search across every file in the folder at once and jump straight to the match.
LIVE DEMO
Try it right here.
Click files, open tabs, search the folder, switch themes, and watch live reload when your "agent" edits the plan. Sample files only; nothing on your computer is read.
Checkout redesign — plan
Written by your coding agent. MDLumen re-renders it every time the file is saved.
Architecture
Drawing diagram…
Tasks
- Split the payment form into steps
- Add address autocomplete
- Write tests for coupon codes
EVERYTHING A GOOD READER NEEDS
Made for long reads and busy agents.
MERMAID
Diagrams drawn, not described.
Flowcharts, sequence diagrams, Gantt charts and more render right in the page, so an agent's architecture sketch reads like a whiteboard.
architecture.md
CODE
Code blocks you can actually read.
Syntax highlighting for the languages you use, with clean monospace type and one-click copy.
export async function applyCoupon(code: string) {
const res = await fetch("/api/cart/coupon");
return res.json();
} LIVE RELOAD
Your agent writes. Your view keeps up.
Keep MDLumen open while Claude Code or Cursor works. Every save appears instantly, and your scroll position stays put.
plan.md · your agent
- [x] Build the cart- [ ] Add coupons- [ ] Add Apple Pay▍MDLumenBuild the cartAdd couponsAdd Apple Pay
QUICK LOOK
Press Space in Finder.
Preview any .md file straight from Finder with the same formatting, diagrams and theme, without opening the app.
README.mdPLAN.mdspec.md
Checkout plan
spaceAlso in every copy
- GitHub-flavored Markdown: tables, task lists, footnotes
- Mermaid diagrams
- Syntax-highlighted code
- Live reload
- Headings outline
- Light, dark and reading themes
- Zoom from 50% to 300%
- Quick Look in Finder
- Export to PDF
- Works offline, files never leave your Mac
ONLY IN MDLUMEN
The parts other viewers leave out.
New
Tabs
Keep many files open and switch in one click.
New
Folder view
Browse a whole project's docs from the sidebar.
New
Search every file
Find text across the folder, not just the open page.
New
Export to Word
Send a polished .docx to people who don't read Markdown.
New
Export to HTML
A clean, self-contained page you can share or host.
New
2-day free trial
Every feature, before you pay anything.
New
1 licence, 3 Macs
Licensed to you, not to a single machine.
COMPARE
How MDLumen stacks up.
Based on each product's public feature list and pricing, October 2026.
| Feature | MDLumen | MacMD Viewer | Free viewers |
|---|---|---|---|
| Mermaid, code highlighting, live reload | Some | ||
| Quick Look preview in Finder | Some | ||
| Tabs for many files | |||
| Folder view of a whole project | |||
| Search across all files | |||
| Export to Word and HTML | PDF only | ||
| Free trial | 2 days | Free | |
| Licence | 1 person, 3 Macs | 1 Mac | — |
| Price | $6.99 once | $19.99 once | $0 |
FOR MAC · PAY ONCE
Choose your licence. Pay once.
Every plan is the full Mac app with every feature, free updates for 1.x, no subscription and no sign-in.
Free trial
for MacTry every feature on your own docs first.
$0USD
2 days · No account · No card
- Everything in Personal
- Starts when you first open the app
- Nothing is charged automatically
.dmg · macOS 14 Sonoma or later
Most popular
Personal
for MacFor you, on up to 3 of your own Macs.
$6.99USD$13.99
One-time · Launch offer, 50% off for the first 50 buyers
- Tabs, folder view and search across files
- Mermaid diagrams, no plugins
- Live reload while your AI agent writes
- Quick Look with Space in Finder and Spotlight
- Export to PDF, Word and HTML
- Syntax-highlighted code
- Daylight, Midnight and Sepia themes
- Outline sidebar with reading time
- Zoom from 50% to 300%
Secure checkout · Licence key by email
Team
for MacOne key per person, each for their own Macs.
$99USD
One-time · 10 keys · $9.90 per person
- Everything in Personal
- All keys in one email, one invoice
- Keys can move between people
Invoice or card · Keys delivered by email
One licence, 3 Macs
Use it on your work laptop and home Mac. Moving to a new Mac is just entering your key again.
Yours after checkout
Your licence key and download link arrive by email. No account, no sign-in.
14-day refund
Not for you? Email us within 14 days for a full refund, no questions asked. All 1.x updates included.
Made for Mac macOS 14 Sonoma or later Apple silicon & Intel (Universal) Works offline Quick Look & Spotlight extension
Prices in USD and exclude tax. VAT, GST or sales tax may be added at checkout depending on your country.
ON WINDOWS?
MDLumen for Windows is next.
Join the waitlist and get the Windows version first, at the launch price.
FAQ
Questions, answered.
What is MDLumen?
A Mac app for reading Markdown, built in Rust on macOS's own WebKit. It turns .md files, such as READMEs, specs and the plans your AI tools write, into clean, readable documents with diagrams, highlighted code and a table of contents. Your files are never changed.
How is it different from other Markdown viewers?
Most viewers show one file at a time. MDLumen opens your whole folder: tabs for many files, a sidebar of every document, and search across all of them. It also exports to Word and HTML as well as PDF.
Does it work with Claude Code, Cursor and ChatGPT?
Yes. Point MDLumen at the folder where your agent writes, and every save shows up instantly through live reload. It works with any tool that writes .md files.
Can I edit files in MDLumen?
MDLumen 1.0 is a reader, so your source files stay exactly as they are. Keep writing in your editor or let your agent write; MDLumen shows the result.
How does the free trial work?
Every feature is free for 2 days from the first time you open the app. There's no account and no card, and nothing is charged automatically. After the trial, buy a licence to keep using it.
How many Macs can I use it on?
One licence is for one person on up to 3 of their own Macs, such as a work laptop and a home desktop. Moving to a new Mac is just a matter of entering your key again.
Is there a subscription?
No. You pay once, $6.99 during the launch offer and $13.99 after, and keep every 1.x update.
Are my files uploaded anywhere?
No. MDLumen renders everything on your Mac and works fully offline. The only network request is the licence check.
Which Macs are supported?
MDLumen runs on Apple silicon and Intel Macs with macOS 14 Sonoma or later. It's built in Rust on macOS's own WebKit, with no Electron, so it stays small and fast.
What if it isn't for me?
Email us within 14 days of buying and we'll refund you in full.
Is there a Windows version?
Not yet. Join the Windows waitlist on this page and you'll get it first, at the launch price.
Your next .md file deserves better than plain text.
Free for 2 days. Then $6.99 once (regular $13.99), with a 14-day refund.
Try MDLumen free