MD ReaderFix: "No app can open this file" for .md files on Android
You tap a .md file and Android says "No app can open this file" (or "Can't open file"). The file is fine. Your phone just doesn't have an app registered for markdown.
Why it happens
Android picks an app based on the file's type. Markdown files are reported as text/markdown, or sometimes as a generic file type. Few pre-installed apps claim those, so Android has nothing to offer.
Fix: install a markdown viewer
- Install MD Reader from Google Play. It registers itself for
.mdand.markdownfiles. - Tap the file again.
- Choose MD Reader (and Always, if you like).
Still not working?
The file type is reported wrongly. Some apps send markdown as an unknown type, so no viewer appears in the list. Open MD Reader, tap Open file, and pick the file from the file picker. This always works.
The file is inside a zip. Extract it first. In Files by Google, tap the zip and choose Extract.
It's an attachment or cloud file. Download it, or use the app's Open with menu. See email attachments and Google Drive.
It opens in the wrong app now. Go to Settings → Apps, find the app that opens it, then Open by default → Clear defaults. Tap the file again to choose.
What if it isn't really markdown?
Some programs use .md for other file types, for example old disk images or game data. If MD Reader shows random symbols instead of readable text, the file probably isn't markdown. A real markdown file is always readable text. See what a .md file is.