Mardo

Native macOS · $29.99 once

Markdown atany size.Still just a file.

A beautiful native Markdown editor built for the way Markdown is used now—by people, tools, and agents.

Buy Mardo 1 · $29.99 → Get the free preview

License delivered now · Mac build preparing · macOS 14+

Native Mac Token-aware Markdown at any size
working-notes.md4 KB ~61 tokens
Rendered Markdown local file · saved
Beautiful when you're writing. Headings, emphasis, revisions, code, quotes, and tasks resolve as you type.

The animation types rich Markdown in working-notes.md, opens agent-memory-50gb.md with no loading state, and finishes the same sentence in the 50 gigabyte file.

Why now

Markdown stopped being human-sized.

A README is still small. The things surrounding it are not. Agents now leave behind research dumps, transcripts, memory files, generated documentation, and logs that keep growing long after a traditional editor would rather they stopped.

The format did not become a database. It is still a wonderfully ordinary file. The editor just has to catch up.

README.md2 KB
research-dump.md200 MB
agent-transcript.md10 GB
memory-and-logs.md50 GB

Same file format. Very different century.

The Mardo difference

Three things worth switching for.

Mardo is not trying to turn Markdown into a workspace, a vault, or a chatbot. It is making the file itself feel effortless again.

01 · SIZE

The file can be huge.
The editor stays small.

Mardo maps the source and renders a bounded band around the viewport. It does not need a second document-sized text object before it can show you the beginning.

Mardo renders what you are looking at, not a second copy of everything you are not.
2 KB

note.md

viewport first
200 MB

transcript.md

viewport first
10 GB

research.md

viewport first
50 GB

agent-log.md

same viewport
02 · TOKENS

The status bar changed because Markdown changed.

Other editors tell you how long a document takes to read. Mardo keeps the unit your tools are actually charging and budgeting around visible.

MARKDOWN THEN

Words · Characters · Reading time

MARKDOWN NOW

~716 tokens ⌄

A bounded estimate from the known byte count and, when needed, at most the opening 64 KiB. No model call. No upload.
03 · COEXISTENCE

Your agent edits the file. Mardo does not panic.

Git, an agent, a formatter, and another editor can all touch the file. Mardo notices replacement and conflict instead of quietly overwriting newer work.

agent writes→Mardo notices→you decide
Reload. Save As. Or deliberately replace the exact version you inspected. Never a quiet overwrite.

Built for AI. Not built around an AI chatbox.

AI made the Markdown.
Mardo keeps it yours.

No document upload. No mandatory account. No proprietary workspace. Use whatever AI tools you want. Mardo handles the ordinary file they leave behind.

DOCUMENT ~/work/agent-evidence.md local · ordinary · yours

The normal stuff is excellent too

A Mac editor.
Not a browser in a trench coat.

Fast is not an excuse to feel austere. Mardo is a calm native editor with the rich Markdown surface people already expect.

#

Rendered editing

Write against a readable document, then reveal the exact Markdown in Source Code mode without changing buffers.

▦

Rich blocks

Tables, tasks, callouts, code coloring, images, math, Mermaid, links, lists, quotes, and six heading levels.

⌕

Find and Outline

Literal Find with next, previous, wrapping and counts, plus an on-demand hierarchical heading outline.

◫

Quick Look

Read, select, and copy Markdown from Finder previews. Large icon tiles reveal the document instead of a generic badge.

◐

Three real themes

MardoDark Graphite, MardoLight Paper, and FloofLogic—compiled palettes with exact native typography, not downloaded CSS.

↗

PDF and Share

Semantic PDF export and native sharing of the original saved Markdown file, using ordinary macOS surfaces.

Lossless by temperament

Mardo does not eat Markdown it does not understand.

If a construct cannot be rendered richly, its source remains visible. Opening a file does not authorize an editor to normalize the interesting parts away.

  • Unknown syntax stays on screen.
  • Copy returns the underlying Markdown source.
  • Explicit Save streams the logical file bytes.
  • No vault, import step, or proprietary library.
vendor-notes.mdUNFAMILIAR · STILL HERE
<vendor:block mode="odd">
  bytes Mardo did not invent
  and will not pretend vanished
</vendor:block>

displayed as source · saved as source

The proof, where it belongs

Want the architecture?
It is all here.

You should want Mardo because it is a beautiful Markdown editor that solves a new problem. The engineering is why it can make the promise.

PERFORMANCE COMPARATOR

Faster than Typora.

Measured on the same Mac, with the same files, across the same cold and warm cases. Useful proof—not Mardo's entire personality.

The engineering contract

Six promises. No asterisks.

The architecture exists to make ordinary product promises true, even when the file stops being ordinary.

01

Instant at any size

Bounded, viewport-first open, seek, edit, and save behavior under fixed time and memory budgets.

02

Faster than Typora

A measured same-hardware comparison, not a vibes-based animation.

03

Full CommonMark

The pinned CommonMark 0.31.2 corpus plus explicitly named extensions through one source-ranged grammar.

04

Lossless display and save

Unfamiliar source stays visible, and unrelated bytes are not normalized away.

05

Safe around external edits

Replacement and conflict become visible decisions instead of silent data loss.

06

Deterministic PDF

A fixed document and fixed policy produce the same pagination and drawing order.

BOUND THE VIEWPORTPIN THE CORPUSMEASURE THE SAME MACSHIP ONLY WHEN GREEN

Mardo 1 personal

One editor.
One price. No account.

$29.99one time · Mardo 1.x updates included

  • Perpetual personal license for Macs you control.
  • Free viewer and 14 active-use days of editing and PDF.
  • Offline certificate. No activation or device counter.
Buy Mardo 1 →

The license is available now. The signed Mac build is not; purchase delivery says that plainly before payment.