Support

Getting started

What do I need?

A Mac running macOS 14 Sonoma or later (Apple silicon or Intel), or an iPhone or iPad running iOS 18 or iPadOS 18 or later. It’s a one-time purchase from the App Store, with no subscription or in-app purchases, and one purchase covers Mac, iPhone and iPad.

Get it on the App Store

How do I open a Markdown file?

• Double-click a .md file in Finder, if MD Viewer is your default app for Markdown (see below).
• Drag a file onto the MD Viewer icon in the Dock.
• Choose File → Open (⌘O) and pick a file.

MD Viewer opens .md, .markdown, .mdown, .mkd, .mkdn, .mdwn, .mdtext and .mdtxt files. To see what it can render, choose Help → Open Sample Document.

How do I make MD Viewer the default app for .md files?

The quickest way is to choose Help → Make MD Viewer the Default for Markdown Files…. MD Viewer selects a Markdown file in Finder and opens a short guide, so you only need to do steps 1–3 below, starting from Get Info. macOS requires you to confirm this change yourself in Finder. To do it by hand:

1. In Finder, select any .md file and choose File → Get Info (⌘I).
2. Under Open with, choose MD Viewer.
3. Click Change All… and confirm.

From then on, double-clicking any .md file opens it in MD Viewer. Repeat for other extensions, such as .markdown, if you use them.

How do I open files on iPhone and iPad?

• Open MD Viewer and browse to the file, in iCloud Drive, On My iPhone/iPad or any storage provider you use in the Files app.
• In the Files app, tap a .md file and choose MD Viewer from the share sheet, or long-press it and choose Open With.
• From another app, such as a Git client, share the file to MD Viewer.

MD Viewer opens files in place, so it shows the file itself rather than a copy, and checking off a task saves to that file. A welcome guide is in the MD Viewer folder the first time you open the app.

The buttons at the top of a document show its table of contents and find text. The ••• menu has text size, appearance, printing, Share or Open In… (to send the file to your editor) and Settings. With a keyboard on iPad, use ⌘F, ⌘R, ⌘P and ⌘+ / ⌘−.

Why don’t my local images show up?

MD Viewer runs in Apple’s App Sandbox, which only lets it read the file you opened. Images and linked documents stored next to that file are off-limits until you allow it.

When a document refers to files MD Viewer can’t reach, a banner appears at the top of the window. Click Grant Access… and choose the folder, usually your project folder. You only need to do this once per folder: MD Viewer remembers it, and it also covers every folder inside.

To see or remove folders you’ve granted, open MD Viewer → Settings and go to Folder Access. You can add a folder there ahead of time too.

On iPhone and iPad it works the same way: tap Grant Access in the banner and pick the folder. Granted folders are listed under ••• → Settings → Folder Access, where you can swipe to remove one.

Images from the web load without any setup, as they would in a browser.

Settings

Can I turn off live reload?

Yes. Open MD Viewer → Settings (⌘,) and turn off Reload automatically when the file changes. You can still reload by hand with File → Reload (⌘R).

On iPhone and iPad the switch is Reload When the File Changes in ••• → Settings, and ••• → Reload reloads by hand. Documents also refresh when you return to the app and when iCloud Drive or another storage provider delivers a new version.

With live reload on, MD Viewer notices every save, including the atomic saves most agents and editors use (write a temporary file, then rename it). Your scroll position is kept, and if you’re at the bottom of the document, the view follows new content as it arrives.

Can I stop MD Viewer from changing my files?

Checking a task box in the preview saves that change to the file. That’s the only way MD Viewer ever writes to a document. To make documents read-only, open Settings and turn off Allow checking off tasks (Check Off Tasks on iPhone and iPad).

How do I choose the editor for ⇧⌘E?

⇧⌘E (Open in Editor) opens the current file in another app. In Settings, use Open in Editor uses to pick one. It lists editors it finds on your Mac, such as VS Code, Cursor, Zed, Sublime Text and BBEdit. For anything else, click Choose Another App…. Automatic uses the first one installed from VS Code, Cursor, Windsurf, Zed, Sublime Text, BBEdit, Nova and TextEdit.

Other handy shortcuts: Show in Finder (⇧⌘R), Copy File Path (⌥⌘C), Print or Save as PDF (⌘P), Find (⌘F, then ⌘G for the next match), and text size (⌘+, ⌘−, ⌘0 for actual size).

Rendering

Do Mermaid diagrams and syntax highlighting need an internet connection?

No. Both are built into the app and work offline. Only images that a document loads from the web need a connection.

Which Markdown features are supported?

GitHub Flavored Markdown: tables, task lists, strikethrough and autolinked URLs. Also GitHub-style alerts (> [!NOTE], TIP, IMPORTANT, WARNING, CAUTION), Mermaid diagrams, syntax-highlighted code blocks with a Copy button, and YAML front matter, shown as a collapsible panel.

A diagram shows an error instead of a picture.

The Mermaid code has a syntax error. MD Viewer shows the message from Mermaid under the source so you can fix it, or ask your agent to. The diagram appears as soon as the corrected file is saved.

Does MD Viewer use AI?

No. MD Viewer has no AI features and never sends your documents anywhere. It’s built for reading the Markdown that AI coding agents, such as Claude Code, Codex, Cursor, GitHub Copilot or Gemini CLI, write into your projects.

Purchases and refunds

MD Viewer is a one-time purchase. There’s no subscription and nothing to unlock later. It’s a universal purchase: buy it once and it’s yours on your Mac, iPhone and iPad.

Refunds are handled by Apple, not by DevPro. To request one, go to reportaproblem.apple.com, sign in with your Apple Account, find MD Viewer and choose Request a refund.

To install MD Viewer on another Mac, iPhone or iPad, sign in to the App Store with the same Apple Account and download it from your purchases at no extra cost.

Contact

Found a bug, or have a question or suggestion? Email mdviewer@devpro.gr. Include your device and its macOS, iOS or iPadOS version and, if you can, the Markdown file that shows the problem.

MD Viewer is made by Kostas Antonopoulos at DevPro.