How to open .md files
It opens in any text editor you already have, showing the asterisks and hashes. Here is how to see it formatted instead, without installing a thing.
Every computer you own can already open this file. Markdown is text, so Notepad, TextEdit, Notes, Mail and every code editor ever written will show you its contents the moment you double-click it. Nothing is missing and nothing needs installing.
What they show you is the source: # heading, **bold**, - bullet. That is correct, and
for a shopping list or a set of meeting notes it is often enough. The reason you are here
is presumably that you want the other view — the one where those marks have turned into
actual headings and actual bullets. For the full background on why one file has two
readable forms, see what a .md file is.
How to open an .md file and actually see the formatting
The shortest route that needs no installing is the markdown editor on this site. Drop the file onto it, or paste text you have already copied, and it renders in the browser tab you are reading this in — nothing is uploaded, and you can confirm that yourself from the Network panel.
It shows the document two ways. Styled is the rendered result. Raw is the file exactly as it sits on disk, so you can compare the two and see which mark produced which piece of formatting. Both views copy, and the styled copy carries its headings and lists into Word, Google Docs or a website editor rather than arriving as a wall of asterisks.
Windows
Right-click the file and choose Open with → Notepad for the source. Windows has no
built-in renderer, so the formatted view has to come from somewhere else — this page, or an
editor such as Visual Studio Code, which previews Markdown with Ctrl + Shift + V.
If Windows insists on opening .md with something unhelpful, it is usually because an
installer claimed the extension. Open with → Choose another app lets you reassign it,
and the checkbox that makes the choice permanent is easy to miss.
Mac
TextEdit opens it, but check one thing first: in Format, TextEdit should be in Plain Text mode. In Rich Text mode it will happily save your Markdown back out as RTF, which quietly replaces the file with something no Markdown tool can read.
Quick Look — select the file and tap the space bar — shows the source without opening anything. Apple’s Notes app also accepts a dragged-in Markdown file and converts it to a formatted note, which is the closest thing macOS has to a built-in viewer.
iPhone and Android
On iOS, tapping a .md in Files usually produces a preview of the raw text, and the share
sheet will hand it to any text app you have. Android behaves the same way through its own
file manager. Neither renders the formatting, so the box above is the shortest route on a
phone: the file picker there reaches iCloud Drive, Google Drive and local storage the same
way any other app would.
A repository you cloned
README.md is the file GitHub renders on a project’s front page, and that rendered version
is often the nicest way to read it — open the project in a browser rather than opening the
file locally. In an editor, VS Code, Sublime Text and their relatives all have a preview
pane, usually one keystroke away.
An export from Notion, Obsidian or a chat assistant
Exports arrive as a folder, sometimes zipped, with one .md per page and an assets
folder beside it holding the images. Unzip before you read anything: previewing a file from
inside a compressed archive breaks the relative image links, which is the usual reason an
exported note looks like it lost its pictures.
Text pasted straight out of a chat assistant is Markdown too, even when it never became a file. Paste it into the panel above and it renders the same way.
Something you were emailed
Some mail clients display a .md attachment inline, others treat it as an unknown binary
and offer only a download. Neither is a sign of trouble. A Markdown file contains no
macros, no scripts and nothing executable — the worst it can do is contain text you would
rather not read.
When you want it to stop being Markdown
Reading it is one job; handing it to someone who does not care about the format is another. Turning the file into a PDF gives you something that looks identical everywhere and needs no explanation. Going the other way, if what you have is a web page rather than a file, converting the HTML to Markdown gets you the clean text. And if you want to change the document rather than just read it, the Markdown editor is the same panel with the writing tools switched on.