How to preview Markdown on Mac now, and what macOS 27.3 fixes

You have two good options today: Quick Look for a fast glance at the text, and an editor preview when you want to see the formatting. Here is how each one works.

Option 1: Quick Look in Finder (raw text until 27.3)

Apple’s own instructions for Quick Look are short:

1. Select the .md file in a Finder window or on your desktop.
2. Press the Space bar. A preview window opens without launching any app.
3. Press the Space bar again, or click the close button, when you are done.

A few extra shortcuts help. Command-Y opens the same preview, Option-Space opens it full screen, and you can also pick Quick Look from the File menu or by Control-clicking the file. If you select several files at once, the arrow keys flip between them, and Command-Return lays them out as a grid. That makes Quick Look handy for sorting a folder of notes or project documents, even before it learns to format them.

Option 2: Visual Studio Code’s built-in preview (formatted today)

This code editor understands Markdown with no add-ons. Its documentation describes these steps:

1. Open the .md file in Visual Studio Code.
2. Press Shift-Command-V to swap the editor for a rendered preview.
3. Press Command-K, then V, to put the preview beside the text instead, so changes show up as you type.

You can also right-click the file’s tab and choose Open Preview, or run the Markdown: Open Preview to the Side command from the Command Palette. The editor keeps the text and the preview scrolled together, and double-clicking something in the preview jumps you to that line in the source.

Apple Notes is a third route for some people. Notes has been able to import and export .md files since iOS 26, and iOS 27 added a Copy as Markdown option plus automatic conversion when you paste Markdown in.

In macOS 27.3, Quick Look draws Markdown the way it was meant to be read. Until this beta, the preview window treated a .md file as plain text, so every pound sign before a heading and every pair of asterisks around a bold word stayed on screen. In the 27.3 beta, headings look like headings, lists are indented and bulleted, links sit inline, and bold text is bold.

The file itself does not change. The new support only affects how the preview displays it, so nothing gets rewritten or converted when you press the Space bar. You also still get the usual Quick Look extras, including an Open with button when you decide you want to edit after all.

For anyone who receives project notes, setup guides or README files (the plain instruction files that ship with a lot of software), this removes a step. You can now check what a document says, and whether its formatting is right, without opening an editor, a notes app or a browser.

Right now, only registered Apple developers can try it, and Apple has not said when macOS 27.3 will reach the public. The beta arrived about a week after macOS Golden Gate 27.2 went out to everyone on October 26.

If you are in the developer program, the path is simple:

1. Open System Settings and click General.
2. Choose Software Update.
3. Opt in to the macOS Golden Gate betas, then install the update.

There are two catches. First, macOS Golden Gate needs a Mac with Apple silicon, so Intel Macs remain on macOS Tahoe and will not get this Quick Look upgrade at all. Second, it is an early beta. Apple already lists a known Siri problem on the Mac in this build, which is a good reminder not to put test software on the computer you rely on for work.

The best timing clue so far comes from the iPhone. Apple has said Apple Intelligence in China will arrive with iOS 27.3 in December. That points to the .3 updates landing around then, but Apple has not tied a date to the Mac version, so treat it as a hint rather than a promise.

Markdown has gone from a writer’s tool to something AI tools depend on. John Gruber created the format in 2004 as a way to write in readable plain text that converts into web pages. A few typed characters do the work: a pound sign makes a heading, asterisks make bold text, and a dash starts a list item.

It spread through software documentation and blogs, and now AI agents use .md files to hold their instructions and background context. Apple is leaning in. Its new Siri AI app skills, which developers can test in the same beta, are written as SKILL.md files that explain to Siri how an app works. Each skill has a name, a one-line description and a Markdown body, and Siri reads the short description first to decide whether a skill fits a request.

Seen that way, Quick Look support is less of a nicety. If Mac users and developers are going to handle more of these files, the system preview needs to show them properly.

For most Mac owners, the payoff is small but frequent: fewer apps opened just to read a file. Here is who gains the most.

• Writers and students who draft in Markdown can check headings and lists with a single key press before sending a file on.
• People using AI chat tools or coding assistants often end up with .md instruction or notes files in their folders, and now those will read cleanly.
• Anyone downloading software gets a readable README without hunting for an app that understands the format.

If you do not want to wait for macOS 27.3, keep Visual Studio Code’s preview shortcut in mind. And if your Mac has an Intel chip, that editor preview, or Notes import, is your long-term answer, since the new Quick Look support will not reach those machines.