Mardo questions and answers

Mardo is a native macOS Markdown viewer and editor. The viewer is free with no time limit; Mardo Pro adds Editing and Export for US $29.99 once. These are the questions people ask most, with the current answers.

Is Mardo free?

Yes. Reading, Finder Quick Look, Find, Outline, Print, Follow Live Edits, and Timewarp are free with no time limit and no account. Mardo Pro adds Editing and Export (HTML, PDF, and the Terminal and MCP export) for US $29.99 once for Mardo 1.x, after a 14-active-use-day trial that you start explicitly from the app.

Do I need an account, and does Mardo send my files anywhere?

No account. Documents never leave your Mac. Send Feedback sends one note only when you press Send, and it never includes your document. Remote images referenced by a document load through a hardened, cookie-free transport, and you can turn them off in Settings.

Does it work with Claude Code, Codex, ChatGPT Desktop, or Claude Desktop?

Yes. Open Mardo → Settings… → AI, select your host, and choose Install for AI Tools…. Mardo then offers four local tools over MCP on standard input and output, with no network port: one shows a file or an exact line range on screen, one returns only the text you have selected, one renders a Markdown file to HTML with Mardo's own exporter, and one sets the command the app runs after an export. The AI guide covers setup and use.

What happens when an agent saves the file I am editing?

Mardo adopts the saved version in place. If you have unsaved edits, changes that do not overlap yours are merged underneath them, with a clone-backed check that proves they are disjoint; changes that overlap pause with a visible marker until you decide. Your viewport and caret stay where they were. Press Command-Y to open Timewarp and step back through every state the file reached while it was open; the Timewarp guide explains the row.

Quick Look shows plain text. What do I do?

On macOS Sequoia and later, enable the extension once: System Settings → General → Login Items & Extensions → Quick Look, and turn on Mardo. From then on, select any Markdown file in Finder and press Space to read it rendered, with selectable, copyable text.

How large a file can Mardo open?

A 50 GiB file opens editable in 124 ms, every jump into it draws in under 13 ms, and the whole file searches in about 38 seconds. Mardo lays out only the region around where you are reading, so a 1 KiB README and a multi-gigabyte log get the same first paint.

Does it run on Intel Macs?

Yes. The archive is Universal for Apple silicon and Intel, and Mardo requires macOS 14 or later.

How do I install it?

With Homebrew:

brew install --cask flooflogic/tap/mardo

Or download the signed, notarized archive from mardo.app and move Mardo to Applications. The cask and the archive are the same build.

How do I open a file from Terminal or reveal a specific line?

Install the mardo command from Help → Install Terminal Command…, then:

mardo plan.md --line 40

The command can reveal a line, an inclusive range, a heading, or a literal match, wait until you close the document, and export HTML without opening a window. The open and create guide has the details.

Which themes are included?

MardoDark, MardoLight, GitHub Light, GitHub Dark, and FloofLogic. Settings can duplicate one into a custom theme, edit it against the live preview, and import or export it as JSON. The themes guide covers zoom and text size.

Current as of September 12, 2026.