How do I open a .md file someone sent me?

The best app on each operating system

Every platform already ships with something that opens a .md file. Every platform also has a better free option one download away. The table shows what you have right now, and what is worth installing only if Markdown becomes a regular part of your week.

Pay attention to the last row. To read one file a colleague sent, installing an app is more work than opening a browser tab. An installed editor only pays off once you write Markdown yourself several times a week.

Tip: On macOS you do not have to open anything at all. Click the file once in Finder and press the space bar, and Quick Look shows the full text on the spot.

What you see, and what it turns into

Here is part of a typical .md file, exactly as it looks in Notepad or TextEdit with no styling applied:

# Release notes

## Version 2.1
- Fixed the **login timeout** bug
- Added a `--verbose` flag

See the [setup guide](docs/setup.md) for details.

> Upgrading is optional this month.

What each symbol becomes

Read raw, that is already clear enough to act on. Rendered, every symbol disappears and turns into formatting instead:

• # becomes the page title, and ## becomes a subheading one level down.
• The two lines that start with - become a bulleted list.
• **login timeout** becomes bold text.
• The backticks around --verbose become a code span, so the double hyphen is not read as prose.
• The bracket-then-parenthesis pair becomes a link labelled "setup guide", pointing at another file in the same folder.
• The > line becomes an indented quotation block.

Watch the conversion happen

Paste that fragment into a preview editor and the change runs line by line as you type. It is the quickest way to connect a symbol to its result, and it takes about a minute. The cheat sheet lists the remaining symbols on a single page.

When it does not open cleanly

Five problems cover almost every awkward case. None of them damages the file, and all five have a fix that takes seconds.

The file arrives as notes.md.txt

Windows hides known extensions, so a well-meant "Save as" turns notes.md into notes.md.txt. The contents are untouched. Switch on File name extensions in the Explorer View tab, then rename the file back.

Chinese or accented characters look like garbage

Symptoms like 中文 mean the editor guessed the wrong encoding. The file is not damaged. Markdown files are UTF-8, so reopen the file with the encoding set by hand. In VS Code that is "Reopen with Encoding", then UTF-8. Never repair mojibake by retyping over it, because the bytes underneath are still correct.

Word or Pages offers to convert it

A word processor will import a .md file happily enough. It then wants to save it back as .docx, with curly quotes replacing straight ones and syntax swallowed by autocorrect.

Watch out: If you do open a Markdown file in Word, never save over the original. Use "Save as" with a new name, or the person who sent it gets the file back with the syntax quietly mangled.

Double-click keeps launching the wrong app

At some point you told the system to always open .md with something unhelpful. Reset it. On Windows, right-click and choose "Open with > Choose another app". On macOS, use Get Info, change "Open with", then click "Change All".

All the line breaks seem to collapse

That is not a fault. Markdown joins consecutive lines into one paragraph, and a blank line starts a new one. A raw file that looks dense on screen still renders as tidy paragraphs, which is the behaviour our complete guide covers under line breaks.

Reading it, editing it, sending it back

Read it in a browser, then export it

The fastest route to a formatted view with nothing to install is the MD Editor. Paste the contents into the left pane and read the preview on the right. From there you can go further than reading. Click .html to download a styled standalone web page, or use Print to save a clean PDF for someone who does not want to deal with Markdown at all.

The full round trip, step by step

1. Open the .md file in any text editor and copy everything.
2. Paste it into the left pane of the editor and read the preview.
3. Make your changes on the left. The preview keeps up as you type.
4. Download the result as a fresh .md file from the toolbar.
5. Send that file back, or export HTML or PDF if the reader prefers it.

Your draft is autosaved in your own browser while you work, so a closed tab is not a lost file. Nothing you paste is uploaded anywhere. The whole round trip happens on your device.

If the file uses tables, task lists or strikethrough, it is written in the GitHub Flavored dialect, which our guide covers element by element. And if you would rather send a finished web page next time, Markdown versus HTML explains which format suits which reader.