Markdown cheatsheet · What opens a .md file
What opens a .md file?
Any text editor will open it, because a .md file is plain text. Whether you can comfortably read it is a different question, and that's the one you're actually asking.
The two-part answer
Anything that opens a text file can open a .md file. Notepad, TextEdit, gedit, your email client's attachment viewer. A .md file is plain text, so nothing is stopping you.
That's rarely what you actually want. Opened in a plain text editor, a README shows up as symbol soup: ## Installation instead of a heading, **important** instead of bold text, [a link](https://…) instead of a link. The file isn't broken. It's just not being rendered.
So the real question is which app renders it, and the answer depends on what you're doing with the file.
What to use, by situation
| What you want | Use |
|---|---|
| Read it, once, right now | Drag it into your browser after renaming to .txt, or paste it into any online viewer |
| Read and edit .md files regularly | A dedicated markdown editor (maxdown, Typora, Obsidian, MarkText) |
| Edit it as part of a codebase | VS Code, or whatever editor you already have open |
| Just see the raw text | Notepad, TextEdit, any text editor |
| Send it to someone who doesn't do markdown | Export to PDF or HTML first |
Every option, honestly
Text editors you already have
Notepad, TextEdit, Notepad++, nano. They open the file instantly and show you the raw markdown. Notepad on Windows 11 now renders basic formatting, which helps a little; see opening .md files on Windows for what it does and doesn't handle. Everything else in this category shows raw text only.
Your browser
Drag a .md file into Chrome or Firefox and you get raw text, because browsers don't render markdown natively. Extensions exist that fix this. It works, but you're installing a browser extension to read a file on your own disk.
Code editors
VS Code opens .md files and has a preview pane (Ctrl+Shift+V). If you already write code, this is free and you're done. If you don't, installing an IDE to read a README is a heavy answer to a light question.
Dedicated markdown editors
Apps built for this: they open the file rendered, and you can edit it without switching modes. This is the right answer if .md files keep showing up in your life. maxdown is free and runs on macOS, Windows and Linux; Typora is $14.99 one-time; Obsidian is free and built around a whole notes system, which is more machinery than "open a file".
Online viewers
Paste-and-render websites. Genuinely useful for a one-off, and no install. The caveat is worth stating plainly: you're uploading the file's contents to someone else's server. For a public README that's fine. For meeting notes or anything internal, it isn't.
What not to use
Also avoid: anything that "converts" the file just to display it. You don't need a converter to read a text file, and converting is how you end up with two copies that drift apart.
Did an AI hand you this file?
If you got here after ChatGPT or Claude gave you a .md file, that's the most common way people meet markdown now, and nothing has gone wrong. AI tools output markdown because it's plain text that carries structure: headings, lists and bold survive a copy-paste that a Word document wouldn't.
You have three sensible options. Open it in any markdown editor to read it properly, which is what the file wants. Rename it to .txt if you only need to skim it once. Or export it to PDF if you have to send it to someone.
Making .md files open in the right app by default
Double-clicking a .md file uses whatever your system decided. That's usually a text editor, and usually not what you want. Both platforms let you change it permanently:
On Linux it depends on your desktop environment; in GNOME and KDE it's the same idea, under "Open With" in the file's properties.
Common questions
Is a .md file safe to open?
Yes. It's plain text, so it can't execute anything. The worst it can do is contain a link you shouldn't click, exactly like an email.
What program opens .md files by default?
None, out of the box, on any OS. That's the whole reason this question gets asked. Windows and macOS both hand .md to a text editor because they don't know what else to do with it.
Can I open a .md file on my phone?
Yes, with a markdown app from your app store. maxdown is desktop only (macOS, Windows, Linux), so it won't help you there.
What's the difference between .md and .markdown?
Nothing. Both extensions mean the same thing; .md just won.