How to open .md files on a Mac

A .md file is a Markdown document: plain text with a few symbols for headings, lists, and links. Your Mac opens it out of the box, but only as raw text. To read it the way it was written to look, open it in an app that renders it.

What a .md file is

Markdown is a way of writing formatted text in a plain text file. A line starting with # is a heading, **this** is bold, and a few pipes make a table. GitHub renders it automatically, which is why every project has a README.md, and coding agents write their instructions and plans in it, which is why your Mac now has CLAUDE.md and AGENTS.md files too.

The file itself is only text. Whether you see a formatted document or a wall of symbols depends on the app you open it with.

Open it rendered in Glance

Glance is a Mac app built for reading Markdown. Double-click a .md file and it opens as a finished page, the way a PDF opens in Preview:

• Headings, lists, and tables in real typography
• Fenced code with syntax highlighting
• Mermaid diagrams and LaTeX math, drawn natively
• Images stored next to the file, and images linked from the web
• ⌘F to search, pinch to zoom, ⌘P to print, and ⇧⌘E to export a PDF

Press Space on any .md file in Finder for the same page in a Quick Look preview, without opening anything. Glance is a native Mac app, 9.8 MB to download, with no account and no vault or library to set up first. Reading is free. If you want to fix a line, click it and type: editing the rendered page is Glance Pro, free for 14 days and then $9.99 once.

Make every .md file open in Glance

Glance offers to become the default app for Markdown the first time you open it, and Settings, General has a Set as Default button if you said no. To do it from Finder instead, select any .md file, choose File, Get Info, pick Glance under Open with, and click Change All.

The other ways, and what you get

TextEdit comes with every Mac. Right-click the file, choose Open With, then TextEdit, and you get the raw Markdown with all its symbols: fine for changing a word, hard to read.

A code editor such as VS Code shows a rendered preview beside the source if you already have one installed: open the file and press ⇧⌘V. It is a developer tool, so expect a project sidebar, tabs, and extensions around one document.

Terminal opens a file in your default app with open README.md, or in Glance specifically with open -a Glance README.md.

Comparing dedicated apps? The roundup of Mac Markdown apps sorts twenty of them by the job they do.

Related

Previews in Finder: how to preview Markdown files in Finder, and what to do when Quick Look shows raw text. One file without a notes app: opening a Markdown file without a vault. Agent files: previewing CLAUDE.md and AGENTS.md.